Chapter 50
Evolution and Consumer Psychology

Gad Saad

Introduction

Consumer behavior is an ideal context from which to study evolutionary principles as applied to humans (Colarelli & Dettman, 2003; Griskevicius & Kenrick, 2013; G. Miller, 2009; Saad, 2006a, 2007a, 2008a, 2011, 2013; Saad & Gill, 2000). We prefer foods that correspond to our evolved taste buds. The spaces where we live, work, or play feel more welcoming when they conform to our biophilic instinct. We purchase products that serve as sexual signals in the mating market (e.g., luxury sports cars and cosmetics for men and women, respectively). We offer gifts as means of forging, maintaining, and strengthening bonds of kinship as well as nonkin friendships and alliances. The romance novels, movie themes, song lyrics, religious narratives, and other cultural products that move us do so because they capture fundamental aspects of our universal human nature. Briefly put, to study consumer behavior is to put a magnifying lens on our evolved preferences, choices, and behaviors.

Given that consumers are biological beings whose minds and bodies have been shaped by the forces of evolution, it is perhaps surprising that the application of evolutionary psychology in consumer behavior is a very recent endeavor. A search on Google Scholar on December 25, 2013, using the conjunction of two search terms “evolutionary psychology” and “consumer behavior” for each year from 1988 through 2013 yielded the following results: 1988–1999: 22 hits; 2000–2005: 133 hits; 2006–2010: 347 hits; 2011–2013: 394 hits. A search through the Handbook of Consumer Psychology (Haugtvedt, Herr, & Kardes, 2008), a 1,273-page edited tome covering the key theories and topics of interest in consumer psychology, revealed that “evolutionary psychology” did not arise once. An analysis of consumer behavior textbooks offers an equally telling demonstration of the lack of evolutionary theorizing within the field. The content is usually quite standardized and includes chapters on perception, learning and memory, attitude formation and attitude change, decision making and information processing, motivation and emotions, personality, and culture. The theoretical frameworks for each of these areas of interest are largely disjointed from one another, yielding an otherwise incoherent view of consumers' minds. Furthermore, there is a (typically implicit) assumption that the human mind is composed of content-independent, domain-general computational systems (e.g., classical and operant conditioning; elaboration likelihood model; theory of reasoned action; rational choice theory).

The idea to Darwinize the field of consumer behavior came to me in fall 1990 during my first semester as a doctoral student at Cornell University when I read Homicide by Martin Daly and Margo Wilson. For approximately the first 10 years of my grand project, I was the sole marketing professor working at the nexus of evolutionary psychology and consumer behavior. Over the past few years, though, a growing number of marketing scholars, many of whom were trained by David M. Buss and Douglas T. Kenrick (two of the leading pioneers of evolutionary psychology), have entered this field and are amassing an impressive body of works. Notwithstanding this growing critical mass of highly talented evolutionary consumer psychologists, the great majority of marketing scholars remain reticent if not hostile to evolutionary theorizing, in part because of their allegiance to a tabula rasa view of the human mind.

Most marketing scholars construe consumer choices as largely driven by socialization. Toy preferences constitute the prototypical example of such a social constructivist viewpoint. The argument is that gender roles are arbitrarily imposed by an otherwise sexist society, the process of which starts early via parentally imposed toy preferences. Little Bob learns to roughhouse by interacting with blue trucks and military action figures while little Bernadette is taught to be demur and nurturing by playing with pink-dressed dolls. With that view in mind, some “new age” parents commit to raising their children with so-called gender-neutral toys, so as to avoid the shackles of “sexist” gender ascriptions. Several independent research streams suggest that this pervasive premise does not bode too well when held up to empirical scrutiny. For example, infants who have yet to reach the cognitive developmental stage to be socialized display the traditional sex-specific toy preferences (Alexander, Wilcox, & Woods, 2009; Jadva, Hines, & Golombok, 2010). Infant vervet and rhesus monkeys have comparable sex-specific toy preferences to those of their human counterparts (Alexander & Hines, 2002; Hassett, Siebert, & Wallen, 2008). Little girls who are affected with congenital adrenal hyperplasia, an endocrine disorder that results in the masculinization of morphological features and behavioral patterns, exhibit toy preferences that are more typical of boys as compared to little girls who do not suffer from the disorder (Berenbaum & Hines, 1992). On a related hormonal note, Lamminmäki et al. (2012) measured infants' testosterone levels (via urine samples) for the first 6 months of their lives, and correlated these with the Pre-School Activities Inventory (PSAI; measures sex-typed behavior) as well as with sex-typed toy choices (train versus baby doll). For boys, testosterone was positively correlated with PSAI scores and negatively with playing with the doll. For girls, testosterone was positively correlated with the amount of time played with the train. Similar correlations have been obtained using proxy measures of androgen exposure. For example, boys with more masculinized left-hand digit ratios (an indicator of androgen exposure in utero) engage in more masculinized play behaviors as measured by the PSAI (Hönekopp & Thierfelder, 2009). Finally, specific design features of toys have been analyzed via an evolutionary lens. Take, for example, the inborn favorable disposition toward baby features. This innate preference has been documented for several products, including car fronts (Miesler, Leder, & Herrmann, 2011) as well as teddy bears. Specifically, a majority of 6-year-old and 8-year-old children prefer teddy bears that possess baby features (Morris, Reddy, & Bunting, 1995). For a review of toy preferences from an evolutionary perspective, see Alexander (2003).

While not all consumer preferences and choices are rooted in evolutionary realities, many could be classified onto one of four key Darwinian clusters: survival, reproduction, kin selection, or reciprocal altruism (Saad, 2006a, 2007a, 2011, 2013; Saad & Gill, 2003). See Garcia and Saad (2008) and Crouch (2013) for applications of these four clusters in neuromarketing and tourism research, respectively. Ultimately, numerous consumer phenomena are rooted in one of these basal evolutionary drivers. In the remainder of this chapter, I offer examples that speak to this reality, within each of the four Darwinian clusters. I conclude with a discussion of some advantages that are reaped via an incorporation of evolutionary theorizing within the field of consumer research.

Survival

Food is central to many of the most fundamental survival challenges, and these include ensuring that one consumes the necessary minimal daily caloric requirements (food foraging) and avoiding becoming part of someone else's caloric count (predator avoidance). These basic drives manifest themselves in myriad of ways within the consumer realm. Humans have evolved gustatory preferences that speak to an ancestral environment in which caloric scarcity was a frequent reality. As such, it is not surprising that consumers exhibit a universal preference for highly caloric and tasty foods (Drewnowski, 1997; Drewnowski & Almiron-Roig, 2010). How do these preferences manifest themselves in terms of actual consumer choices? Whether one ranks the leading restaurant chains in the United States alone or expands the analysis globally, the same set of companies appear on any such list and includes McDonald's, KFC, Wendy's, Pizza Hut, and Burger King. These companies are globally successful because they offer products that are in line with our evolved gustatory preferences. The menus might be tweaked to fit culture-specific requirements (e.g., McDonald's adheres to Hindu beef restrictions in India), but the universal commonality is that the food items are highly caloric and fatty.

Marketing academics wrongly presume that evolutionary psychologists are singularly focused on identifying cross-cultural similarities (human universals). They posit that actionable marketing strategies typically seek to understand consumer heterogeneity, be it at the individual or cultural level. Of course, this is a false premise in that evolutionary theory fully recognizes that many cross-cultural differences are rooted in adaptive processes, and as such are well within the meta-framework's purview (e.g., Gangestad, Haselton, & Buss, 2006). Take cross-cultural differences in culinary practices. Why are some cuisines more meat-based while others are nearly bereft of meat? Why do some gastronomical traditions make greater use of spices, pickling, or smoking than others? How does salt consumption vary across cultural settings? Several researchers have demonstrated that culinary traditions serve as adaptations to a very real biological problem, namely, the density of pathogens within a local niche, which is correlated to the ambient temperature in that local climate (antimicrobial hypothesis). Hotter climates (due to geography and/or seasonality) are likely to contain greater food pathogens, and as such, one would expect the adoption of culinary practices (e.g., more pronounced use of spices) that quell that threat (Billing & Sherman, 1998; Ohtsubo, 2009; Sherman & Billing, 1999; Sherman & Hash, 2001). Of note, Zhu et al. (2013) demonstrated that culinary traditions across regions of China adhere to a copy-and-mutate mechanism based on geographical proximity.

Culturally and religiously sanctioned food taboos have also been explored from an evolutionary perspective. While most cultural anthropologists are satisfied at merely documenting varied food restrictions across cultures, evolutionary-minded scholars examine whether these might be rooted in biological realities. For example, Henrich and Henrich (2010) showed that Fijian food taboos serve as shields against otherwise harmful marine toxins. Saad (2011) argued along similar adaptive lines regarding the kosher prohibition against the consumption of shellfish. Other environmental contingencies could also alter one's food-related behaviors. Using a life-history perspective, Laran and Salerno (2013) exposed participants to cues of environmental harshness and found that their food choices were more likely to converge on alternatives that were perceived as being highly caloric and filling. In other words, priming people about harsh settings triggers a caloric hoarding mechanism.

There are countless other food-related items of relevance to consumer scholars that speak to evolved biological mechanisms. These include how food preferences are passed from mother to child in utero or during breastfeeding (Beauchamp & Mennella, 2009; Mennella, Jagnow, & Beauchamp, 2001); women's food cravings and aversions during gestation (cf. Sherman & Flaxman, 2001); the link between women's food-related behaviors and preferences and their menstrual cycles (Fessler, 2001; Saad & Stenstrom, 2012); the evolved penchant for food variety, even in instances when objectively speaking, the varied offerings are identical in terms of their taste or smell (e.g., manipulating the number of colors of M&M candies or the number of distinct pasta shapes; Kahn & Wansink, 2004; Rolls, Rowe, & Rolls, 1982); the positive relationship between situational hunger and food-related attitudes and purchases (Lozano, Crites, & Aikman, 1999; Nisbett & Kanouse, 1969); and the adaptive ways by which people recall the location of high-calorie food items (Allan & Allan, 2013; New, Krasnow, Truxaw, & Gaulin, 2007).

While it is clear that food is central to survival, it also plays an important role in various mating-related rituals across a wide range of species, including humans. In some instances, nuptial gifts amount to offerings of food, in which case there is a clear implicit contract: food for sex. Nowhere is this economics of sex exchange more explicit than in species that engage in sexual cannibalism (e.g., some spider and praying mantis species; Buskirk, Frohlich, & Ross, 1984). In the human context, many courtship rituals revolve around food (e.g., a first date, Valentine's dinner, wedding banquet), and couple intimacy is in part signaled by the extent to which the two individuals share food with one another (Alley, Brubaker, & Fox, 2013; L. Miller, Rozin, & Fiske, 1998). People are more jealous when they have to imagine their current romantic partners sharing a lunch or dinner date with an ex-lover as compared to imagining similar encounters not involving food (Kniffin & Wansink, 2012).

Beyond food, there are other consumer-related phenomena that map onto the survival cluster including individuals' inborn preferences for particular environments (e.g., natural landscapes; man-made spaces). Many marketing scholars have explored how commercial atmospherics (e.g., background music in a mall; ambient smell in a retail store) affect consumer outcomes, albeit these works have not been rooted within an evolutionary framework (for relevant reviews, see Krishna, 2012; Turley & Milliman, 2000). There are at least two evolutionary-based frameworks that could contribute to this literature: prospect-refuge theory (Orians & Heerwagen, 1992) and the biophilia hypothesis (Wilson, 1984). The former proposes that humans have an innate preference for natural landscapes that permit for a wide visual prospect whilst affording refuge (Falk & Balling, 2010) precisely because this protects against predators and other environmental menaces (e.g., hostile outgroup members). These instinctual spatial preferences can inform how one designs a multitude of man-made environments, including retail stores (Joye, Poels, & Willems, 2011) and interior spaces (Scott, 1993). The biophilic instinct refers to our innate desire to seek communion with nature, as evidenced by the fact that there are countless psychological, emotional, and physical benefits that are reaped by interacting with the natural world (Maller, Townsend, Pryor, Brown, & St Leger, 2006). Optimal architectural, urban, and interior designs are in part defined by the extent to which they cater to our biophilic instinct. The few studies that have applied these evolutionary principles within a consumer/business setting include the benefits of incorporating scenes of nature in green advertising (Hartmann & Apaolaza-Ibáñez, 2010), the use of trees in designing optimal business districts (Wolf, 2005), the preference for shiny items and products as an instantiation of humans' inborn need for fresh water (Meert, Pandelaere, & Patrick, 2013), and individuals' reduction of future discounting (i.e., greater willingness to delay gratification) subsequent to viewing photos of natural landscapes or strolling in a forest (van der Wal, Schade, Krabbendam, & van Vugt, 2013).

Mating

There are many ways by which mating-related issues manifest themselves within the consumer setting. First, the contents of cultural products (e.g., pornographic films, advertising) could be analyzed to highlight evolved aspects of human nature in general and human sexuality in particular (Saad, 2004, 2012). Pound (2002) conducted a content analysis of pornographic materials (films and photos) that were produced for the viewing pleasures of men, and found that polyandrous depictions were much more frequent than their polygynous counterparts. He theorized that this was driven by the excitatory visual cues associated with sperm competition. Kilgallon and Simmons (2005) obtained support for Pound's premise by having men either masturbate to pornographic photos containing polyandrous depictions (one woman with two men) or not (three women together). They found that samples stemming from the polyandrous image possessed a greater percentage of motile sperm (motility is positively correlated with fertility). The sales rank of pornographic DVDs is correlated to the frequency of polyandrous images on the DVD covers (McKibbin, Pham, & Shackelford, 2013). In addition to having a direct impact on sales, evolutionarily relevant stimuli affect an advertisement's efficacy. Vyncke (2011) examined whether the manipulation of an endorser's evolutionarily relevant features (e.g., facial symmetry, waist-to-hip ratio, or skin quality) might enhance an ad's likability. Participants were shown 80 pairs of advertisements (neutral and manipulated versions) to gauge the effects of incorporating fitness-enhancing advertising cues. Sixty-nine out of the 80 pairs of ads yielded results in line with the evolutionary predictions; 7 produced findings that were contrary to the evolutionary expectations; and 4 bore no effects. In other words, successful advertisements are precisely those that cater to our evolved preferences.

Beyond analyzing cultural products for their mating-related content, one could investigate how consumers utilize products as sexual signals, the classic example of which is conspicuous consumption. Most marketing scholars who have studied conspicuous consumption have done so without recognizing that it is a form of sexual signaling (Saad, 2007a). That said, several recent studies have situated ostentatious consumer displays within the biological realm. Using a within-subjects field experiment, Saad and Vongas (2009) examined the effects of conspicuous consumption on men's testosterone levels. Participants drove a 2006 Porsche and an old decrepit 1990 Toyota sedan both in a highly public environment (downtown Montreal) and in a less public setting (semi-deserted highway). Salivary assays were collected after each of the four driving conditions, and these were compared to baseline measures to gauge how cues of social status would alter men's testosterone levels. Driving a high-status car yielded an increase in men's T levels (in both the public and private settings), as this serves as a powerful signal to a man's social standing. Of note, viewing photos of sports cars also increase men's salivation, but only when they are primed about mating (Gal, 2012).

While the use of biological substrates in the study of conspicuous consumption is quite rare, experimental priming remains the most frequent paradigm within this area of research. Griskevicius and colleagues (2007) primed men with mating-related stimuli (e.g., photos of desirable women), and this increased their stated proclivity to engage in conspicuous consumption. Sundie and colleagues (2011) built on this work by demonstrating that conspicuous consumption is more likely to be used by men pursuing short-term mating opportunities. Furthermore, women are attracted to men who engage in such showy behaviors, but only as prospective short-term partners (and not as marriage suitors). On a related note, Janssens and colleagues (2011) demonstrated that single men who were primed with a photo of a scantily clad woman were more likely to recall status products than their counterparts who were shown the same woman but in plain clothes. So when men are primed with mating cues, they appear to differentially focus on products that might be used as sexual signals to woo women. While most research has explored conspicuous consumption as a male-based form of sexual signaling, Wang and Griskevicius (2014) recently examined how women utilize this strategy as a means of warding off same-sex rivals.

There are numerous benefits that accrue to men who engage in conspicuous consumption. Guéguen and Lamy (2012) recently established the links between the status of the car that a man is driving and his likely success in the mating market. They demonstrated that women's likelihood of accepting a request for their phone numbers was contingent on the status of the car in which the soliciting man was seated. The compliance rates across the high-, middle-, and low-status cars were 23.3%, 12.8%, and 7.8%, respectively. Dunn and Searle (2010) asked men and women to rate the physical attractiveness of opposite-sex targets who were either seated in a pricey Bentley or in an inexpensive Ford Fiesta. While men's ratings of the female target were unaffected by the car that she was seated in, women's evaluations of the same man were higher when he was associated with the Bentley. So the Bentley's “status glow” seeps its way onto a man's morphological features. Dunn and Hill (2014) obtained similar findings using photos of male or female targets that were shown in one of two apartments that varied in terms of their luxury levels. Participants were asked to rate the physical attractiveness of opposite-sex targets. The apartment's luxury level did not affect men's ratings, while women's evaluations were very much dependent on which of the two apartments the same man was shown in: Greater luxury yielded higher attractiveness scores. Saad and Gill (2014a) created two versions of a man's online dating profile, one element of which was for the individual to show his favorite possession (photo of the product was included). The product was manipulated to be either a luxury brand or its inexpensive counterpart across two categories (Porsche versus Kia; Rolex versus Casio). The objective was to gauge participants' impressions of the individual as a function of which product he was associated with. His comparative height (in relation to the participant) was perceived quite differently depending on whether he was being judged by male or female participants. Intrasexual rivalry led men to reduce his perceived height (status contraction effect), while women increased his height (status elongation effect). These perceptual biases are rooted in the evolutionary calculus that regulates same-sex derogation and intersexual wooing.

The status of a man's clothes constitutes another crucial determinant to his perceived attractiveness on the mating market. Townsend and Levy (1990) manipulated a target's status via the clothes that he/she wore (Burger King uniform, off-white shirt, or fancier clothes and Rolex watch), and asked opposite-sex participants to rate the target's physical attractiveness as well as their willingness to engage in one of six types of relationships with the target: coffee and conversation; date; sex only; serious involvement, marriage potential; sexual and serious, marriage potential; and marriage. The effect of costume status was greater for female participants across all six relationships, and only the physical attractiveness of the male target was affected by his costume status. In other words, in the mating market, the status of an individual's clothes carries much greater weight for women (when judging men) than it does for men (when judging women). When facing a choice between immediate versus delayed monetary rewards (intertemporal choice), both sexes are influenced by clothes-based sexual primes albeit different senses are operative. For men, the sexual prime has to be elicited visually, namely, exposure to scantily clad women (e.g., wearing bikinis or lingerie) results in a greater desire for immediate rewards (van den Bergh, Dewitte, & Warlop, 2008). For women, tactile cues appear to be the operative modality such that subsequent to touching men's boxer shorts they exhibit a greater penchant for immediate rewards (Festjens, Bruyneel, & Dewitte, 2013). Beyond clothes, other beautification-related issues that have been explored from an evolutionary perspective include high heels (Morris, White, Morrison, & Fisher, 2013), cosmetics (Etcoff, Stock, Haley, Vickery, & House, 2011), perfumes (Milinski & Wedekind, 2001; Roberts & Havlicek, 2012), hairstyles (Hinsz, Matz, & Patience, 2001; Mesko & Bereczkei, 2004), hair color preferences (Hinsz, Stoesser, & Matz, 2013), and men's facial hair (Dixson & Brooks, 2013). Generally speaking, such studies demonstrate how a given product or service caters to an evolved sex-specific preference (e.g., high heels lift a woman's buttocks by at least 20 degrees and as such create a more youthful figure—see Smith, 1999, and relevant references therein; cosmetics accentuate a facial contrast sexual dimorphism—Russell, 2009).

While some beautification elements are universally operative (e.g., preference for facial symmetry), others are influenced by evolutionarily relevant situational factors. Several evolutionary-minded scholars have established that both women's fashion styles (e.g., hemlines) as well as their spending on beautification products are affected by environmental contingencies such as economic conditions and sex ratios (Barber, 1999; R. A. Hill, Donovan, & Koyama, 2005; S. E. Hill, Rodeheffer, Griskevicius, Durante, & White, 2012). So in the same way that culinary traditions are cultural adaptations to local niches (e.g., extent of spice use as a function of the density of pathogens), fashion cycles and beautification spending are manifestations of adaptive behavioral plasticity. These studies dispel the common misconception that evolutionary psychology posits rigid and nonmalleable deterministic processes (Confer et al., 2010). Of all situational variables that operate within the mating domain, the menstrual cycle is perhaps the most frequently studied. In their theoretical treatise of how evolutionary psychology could inform the field of marketing, Saad and Gill (2000) argued that menstrual cycle effects should be prevalent within the consumer setting. Numerous researchers have since explored this exact link. Faraji-Rad, Moeini-Jazani, and Warlop (2013) found that women exhibited greater variety seeking in rewards during the fertile phase both in the food and mating domains. Pine and Fletcher (2011) examined women's scores on the Recent Spending and Saving Scale (RSSS) across three time periods of the menstrual cycle. RSSS scores were higher in the luteal as compared to the follicular phase, namely, women's spending behaviors were more impulsive and less controlled in the premenstrual phase (lesser ability to self-regulate). Perhaps the most documented phenomenon, though, has been that women are more likely to engage in signaling (e.g., wearing sexy clothes) when maximally fertile (cf. Durante, Griskevicius, Hill, Perilloux, & Li, 2011; Saad & Stenstrom, 2012). In a context where a woman's capacity to sexually entice is linked to her livelihood, G. Miller, Tybur, and Jordan (2007) found that exotic dancers received larger tips when in the ovulatory phase of their menstrual cycles. The color red has been shown to augment a woman's perceived attractiveness and sexual desirability as judged by men (Elliot & Niesta, 2008), and this red effect applies to women of reproductive age only (Schwarz & Singer, 2013) and appears to be a universal excitatory cue, as it has been demonstrated in numerous cultures, including in an isolated society of Burkina Faso (Elliot, Tracy, Pazda, & Beall, 2012). It is perhaps not surprising, then, that women are more likely to wear red and pink hues when they are in the maximally fertile phase of their menstrual cycles (Beall & Tracy, 2013).

Beyond an increase in their own sexual signaling when maximally fertile, women exhibit a perceptual bias toward male-based sexual signals when ovulating. Subsequent to being shown both status and functional products, women recalled a greater number of the former (conspicuous and expensive products) and did so earlier in the recalled lists when in the fertile phase of their cycles (Lens, Driesmans, Pandelaere, & Janssens, 2012). Although most menstrual effects focus on intersexual signaling, some are shaped by intrasexual rivalry. For example, women's economic decisions (e.g., the offers they make when playing the dictator game) are driven by same-sex competition but only so during the ovulatory phase of their menstrual cycles (Durante, Griskevicius, Cantú, & Simpson, 2014).

Gift Giving: Mating, Kin Altruism, and Reciprocal Altruism

Kin selection (Hamilton, 1964) and reciprocal altruism (Trivers, 1971) are two of the basal Darwinian mechanisms that shape human sociality, both of which manifest themselves within the universal ritual of gift giving. Perhaps no gift is more profound than the proverbial gift of life as instantiated by living organ donations. Not surprisingly, though, such gifts are almost always made to kin and very rarely to close nonkin (e.g., friends), let alone to strangers (for relevant references, see Saad, 2011, p. 311, footnotes 17–19). The practice of gifting one's kidney to a total stranger (known as a Samaritan donation) is so counterintuitive and rare that in most instances it has been frowned upon, as this might serve as a signal to the altruist's mental instability (Kranenburg et al., 2008). Clearly, then, gifts are meted out according to an evolutionary calculus that is in part driven by genetic relatedness. In the consumer setting, the exchange of gifts is a wonderful venue from which to explore a wide range of evolutionary motives. Saad and Gill (2003) asked men and women about the reasons that drive them to offer gifts to their romantic partners. These were classified as tactical (displaying financial resources; creating a good impression; as a means of seduction; showing affection; displaying long-term interest; and displaying generosity) or situational (occasion demanded it; reconciliation after a fight; to reciprocate). As expected from an evolutionary perspective, men scored higher on five of the six tactical motives (the only one that did not yield a sex difference was “displaying generosity”), while the two sexes did not differ on any of the three situation motives. Men utilize romantic gift giving as an integral and tactical element of the courtship ritual. Cronk and Dunham (2007) examined perhaps the grandest of all mating-related gift giving rituals: a man's offering of an engagement ring to his prospective bride. The cost of the ring was negatively correlated to a bride's age (young female age being linked with high reproductive value).

Using the same set of six tactical and three situational motives, Saad and Gill also collected participants' perceptions as to why they thought their partners offered them gifts. The goal was to see whether men and women are equally calibrated in understanding how their own motives might be different from those of their partners when it comes to romantic gift giving. While no differences were found along situational motives for either sex, tactical motives yielded profound sex differences. On all but one of the tactical motives, men thought that their motives and those of women are the same. On the other hand, on all but one of the six tactical motives, women recognized that men were much more likely to be driven by such motives than they were. In other words, women are very accurate and men grossly inaccurate in understanding the signals inherent to romantic gift giving. From an evolutionary perspective, this makes perfect sense in that the costs of misreading such gift-giving signals loom much larger for women, not unlike the sex difference in the ascription of sexual intent stemming from, say, a smile, as outlined according to error management theory logic (Haselton & Buss, 2000).

Gift giving does not solely manifest itself in the mating arena. It is also a ritual that is universally used to forge, strengthen, and deepen bonds of affiliation among kin and nonkin alike. One would also expect that the cost of a gift would be in part determined by the strength of the relationship between giver and recipient. Saad and Gill (2003) documented a correlation between the genetic relatedness of gift givers and gift recipients and the amount of money to be spent on a gift. Furthermore, of all possible recipients, individuals planned to spend the most on their mates ($106.43), followed by closely genetically linked individuals (r = 0.50; $73.12), close friends ($46.34), moderately close kin (r = 0.25; $19.03), and more distant kin (r = 0.125; $18.56). Stepfamilies and others had mean gift sizes of $19.37 and $27.03, respectively.

While Saad and Gill collected data on the estimated amounts to be spent on future gifts, Tifferet, Saad, Meiri, and Ido (2014) investigated actual monetary gifts at Israeli weddings. The genetic relatedness effect was replicated in that guests who were close kin (r = 0.50 and r = 0.25) gave larger sums to the brides and grooms than gifts of more distant kin (r = 0.125 and r = 0.0625). Furthermore, genetically related guests offered larger monetary gifts than their nonkin counterparts. Note though that kin-based investments are not solely driven by genetic relatedness but are also affected by genetic assuredness (i.e., the certainty of the genetic link). While matrilineal relationships are genetically assured (e.g., the link of a maternal grandmother to her grandchildren), patrilineal ones are fraught with paternity uncertainty (e.g., the paternal grandfather-to-grandchild relationship has two sources of potential cuckoldry). Several evolutionary-minded scholars have shown that investments are affected by this genetic assuredness effect across grandparents, uncles, and cousins (Euler, 2011; Euler & Weitzel, 1996; Jeon & Buss, 2007; Júnior, Dunbar, & Brito, 2014; Pashos & McBurney, 2008). Using this evolutionary principle, Tifferet et al. (2014) showed that the matrilineal side of the newlyweds gave larger monetary gifts than their patrilineal counterparts. This finding would have been difficult to predict, let alone uncover, void of the requisite evolutionary lens.

Homo consumericus: Theoretical, Epistemological, and Methodological Benefits

In an editorial published in one of the premier journals of consumer research, Michel Pham, the recent president of the Society for Consumer Psychology, identified seven problems of the field, including “(1) a narrow conception of the scope of consumer behavior research; (2) adoption of a narrow set of theoretical lenses; (3) adherence to a narrow epistemology of consumer research” (Pham, 2013, p. 411). I contend that each of the seven problems would be attenuated if evolutionary psychology were adopted as the meta-framework for understanding consumer behavior (see also Kenrick, Saad, & Griskevicius, 2013). In two of my books (Saad, 2007a, 2011), I offer an all-encompassing evolutionary-inspired definition of consumer behavior that goes well beyond the standard scope covered by consumer scholars. Evolutionary psychology offers a meta-theoretical framework that encompasses broad middle-level theoretical approaches (Buss, 1995; Ketelaar & Ellis, 2000), all of which are organized into a coherent tree of knowledge. Furthermore, it expands greatly the epistemological realm of consumer research by recognizing the import of both proximate as well as ultimate explanations for any given phenomenon involving biological beings. In their editorial in the Journal of Consumer Research, Deighton, MacInnis, McGill, and Shiv (2010) ask of consumer scholars to broaden the scope of their investigations in one of several ways, including “providing new ways of thinking about an important aspect of consumer behavior” or working to “develop an elegant higher-order parsimonious perspective that both accommodates past findings and accounts for anomalous ones.” (p. vi). Evolutionary psychology caters to both objectives in that it provides the epistemological footing to explore consumer phenomena in new ways (e.g., at the ultimate level), and it is the integrative framework par excellence that can engender consilience (Wilson, 1998) to a discipline that is otherwise disjointed and largely incoherent (November, 2004; Saad, 2007a, Ch. 7; Saad, 2008a; Saad, 2011, Ch. 11; Saad, 2013).

By virtue of their methodological focus (Sternberg & Grigorenko, 2001) on conducting “clean” laboratory studies, many consumer psychologists suffer from what I refer to as epistemological dichotomania. In sum, they subscribe to the notion that countless cognitive processes exist in binary and typically mutually exclusive forms (e.g., heuristic versus systematic processing; implicit versus explicit categorization; central versus peripheral routes of persuasion; prevention versus promotion self-regulatory focus). Even within a particular subfield of marketing such as advertising copy, the world is viewed through the prism of binary realities: one-sided versus two-sided messages; rational versus emotional appeals; simple versus complex messages; cosmetic versus substantive executional ad changes. This epistemological penchant shackles consumer researchers into viewing the natural world through the rarified and limiting world of 2×2 factorial designs. Given the methodological pluralism inherent to the evolutionary behavioral sciences, this narrow focus is much less likely to occur among evolutionarily informed consumer psychologists. Take, for example, men's near-universal preference for women to possess a waist-to-hip ratio of 0.70. Evolutionary psychologists have utilized a bewildering number of methodological approaches and dependent measures to establish the veracity of this premise, including cross-cultural preferences, via the use of line drawings as well as actual photos of women's bodies pre- and postoperative cosmetic surgeries (see Singh, Dixson, Jessop, Morgan, & Dixson, 2010 and relevant references therein); content analyses of Indian, African, Greek, and Egyptian art spanning several millennia (Singh, 2002); content analyses of online advertisements of female escorts across 48 countries (Saad, 2008b); brain imaging and eye-tracking studies (Dixson, Grimshaw, Linklater, & Dixson, 2011; Platek & Singh, 2010); and the preferences of congenitally blind men as elicited by touch (Karremans, Frankenhuis, & Arons, 2010). Not only does this serve as a telling demonstration of the methodological pluralism that evolutionary psychology engenders, but also it belies a common, but typically erroneous, attack on evolutionary psychology, namely that the field consists of hand-waving just-so story-telling (Confer et al., 2010). Evolutionary behavioral scientists test their theories using an evidentiary threshold that is typically set astoundingly higher than that typical of the social sciences.

In their analysis of the disciplinary status of the field of consumer behavior, MacInnis and Folkes (2010) concluded that it is neither an independent field of inquiry (but rather is subsumed within the marketing discipline) nor an interdisciplinary one. Scholars who publish in the leading consumer journals (e.g., Journal of Consumer Research, Journal of Consumer Psychology, Journal of Marketing Research) are overwhelmingly housed in marketing departments. Furthermore, members of the premier society of consumer researchers (Association for Consumer Research) are nearly fully composed of marketing scholars. This is in stark contrast with the members who belong to the leading evolutionary psychology society (Human Behavior and Evolution Society), which has representatives from more than 30 disciplines across the natural sciences, social sciences, and humanities. Garcia and colleagues (2011) compared first authors' departmental affiliations of articles published in two of the leading evolutionary psychology journals (Evolution and Human Behavior and Evolutionary Psychology) to those published in eight other leading psychology journals (two each from the general categories of neuroscience, cognitive psychology, learning/behaviorism, and psychodynamic psychology). A total of 1,000 articles were analyzed (100 articles for each of the 10 journals). The evolutionary psychology journals contained a greater proportion of first authors who were housed in departments other than psychology and they originated from a broader number of fields. The reason for this interdisciplinary is quite simple: Evolutionary psychology is a meta-framework that serves as an epistemological key that can be applied seamlessly across intellectual landscapes. This is precisely the reason that in my own career I have published evolutionary-based works spanning highly disparate and heterogeneous topics including the effects of birth order in understanding consumer conformity and adoption of innovations (Saad, Gill, & Nataraajan, 2005), sun tanning (Saad & Peng, 2006), the framing effect when evaluating prospective mates (Saad & Gill, 2014b), sex differences in sequential mate choice (Saad, Eba, & Sejean, 2009), sex differences when playing the ultimatum and dictator games (Saad & Gill, 2001a, 2001b), financial risk taking and pathological gambling (Stenstrom & Saad, 2011), and a slew of psychiatric conditions, including obsessive-compulsive disorder (Saad, 2006b), suicide (Saad, 2007b), and Munchausen syndrome by proxy (Saad, 2010).

Radical scientific innovations arise in one of several ways. At times, novel research streams remain hidden until the appropriate methodological tools have been developed (e.g., the electronic microscope, the telescope, brain imaging, genotyping). In other instances, a new epistemological lens is needed to open new lines of discovery. Evolutionary psychology offers a powerful epistemological key to unlock unchartered territories. In recognizing the epistemological benefits of ultimate-level explanations and the associated adaptive proximate mechanisms, consumer scholars are bound to identify novel research questions and generate findings that would have remained otherwise concealed (Saad & Gill, 2000; Saad, 2007a). Take, for example, the finding that women are more likely to purchase beauty-related products when primed to think about economic recessions (S. E. Hill et al., 2012). At first glance, this appears counterintuitive, as one might expect that hard economic times would yield a decrease in such sales (since less disposable income is likely available). However, using an evolutionary lens, Hill and her colleagues reasoned that during economic hardships, fewer men with resources are to be found thus causing women to engage in more vigorous sexual signaling (instantiated via greater beautification). This example and countless others discussed in this chapter demonstrate the distinct explanatory power afforded by an evolutionary lens. Consumer scholars should not construe evolutionary psychology as a threatening framework bent on taking over their existing research programs. Rather, in most areas of interest to consumer scholars, the evolutionary perspective offers a complementary toolbox of organizing principles that only enriches the depth and richness of existing explanations.

Concluding Remarks

In the 15-plus years that I have been Darwinizing the field of consumer behavior, I have been exposed to a wide range of criticisms and attacks, some of which are applicable to evolutionary psychology in general, while others are unique to the consumer behavior field (cf. Saad, 2008a; Saad, 2011, pp. 22–32). Some believe that findings stemming from the field of evolutionary consumer psychology are dangerous in that they can be “misused” to justify reprehensible realities. This is what a librarian from the University of Toronto wrote me subsequent to having read about the results reported in Saad and Stenstrom (2012) regarding women dressing more provocatively during the fertile phase of their menstrual cycle: “Perhaps you have not noticed that this is a highly problematic contention, not least as it is still used as a defense for rapists.” Others dislike the fact that the same evolutionary mechanisms that explain animal behavior could be operative in elucidating consumer behavior. Here is what one clinical psychologist thought of my drawing behavioral homologies and analogies between consumers and our animal cousins (from http://modernpsychologist.ca/delusions-of-a-consuming-instinct/):

For our purposes, we might simply note that right from the start Saad is looking to compare us with monkeys, and that he is emphasizing our innate animal nature, believing it holds the ultimate causal explanation for many of our everyday human behaviors…

Saad claims that we have a similar “instinct” for “hoarding and gorging,” but since we do not have the same metabolic rate, as say a hummingbird, we are left with the current American obesity crisis and other “dreadful diseases.” Note how quickly Saad went from comparing us to monkeys (and monkeys to us) and now to hummingbirds. I am less comfortable in making such comparisons, but let us set that point aside for the moment—we will pick it up again later.

His quotes are emblematic of the reaction of many consumer psychologists. For example, subsequent to my 2007 academic book being published (Saad, 2007a), I had been invited to discuss my evolutionary consumption work at one of the leading marketing departments in the world. I faced an endless litany of hostile interruptions, including one of relevance to the current issue: “Are you suggesting that we [consumers] are animals?” asked with an air of loathing, if not outright disgust. The tide is changing, though, as evidenced by the fact that Vicky Morwitz, the 2011 president of the Society of Consumer Psychology conference, recently published a paper highlighting how an exploration of animal cognition could be used to better understand consumers' minds (Morwitz, 2014).

Despite some continued resistance to the notion that consumers are biological beings whose bodies and minds were designed by evolution, such detracting voices are on the losing end of the grand Darwinian debate. Consumer behavior exists within the biological realm and not in some parallel universe where evolution ceases to matter. Notwithstanding the myriad of ethnic, cultural, religious, linguistic, and racial differences that enrich the human tapestry, Homo consumericus unites us via our shared biological heritage.

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