Observations of child maturation by developmental theorists are foundational for pediatrics, child psychiatry, and child psychology. The work of many different theorists over the years (e.g., Beloglovsky and Daly 2015; McCartney and Philips 2006; Mooney 2013) has resulted in a diverse set of child developmental theories that are intended to help us understand what happens during child development. Surveying the entirety of this literature is beyond the scope of this text. Instead, we discuss specific observable milestones within child development and their recognized patterns of appearance.
Milestones are recognizable skills or abilities that have an expected range and order of appearance, such as a child taking his first step around the time of his first birthday. Identifying any significant variations from expected patterns, such as a child taking that first step near his second birthday, is a key task for any practitioner. Knowing when a significant variation in development has occurred improves diagnostic accuracy because DSM-5 (American Psychiatric Association 2013) specifically requires consideration of developmental stages. The most important consideration is that the sooner a significant developmental impairment is identified and addressed, the better the long-term outcomes could be for your patients.
Identifying milestones is a particularly important skill set for practitioners working with children younger than 5 years, but we all need to be familiar with milestones because nonsevere developmental impairments frequently go unrecognized until children are much older. Five different milestone skill areas should be evaluated: gross/fine motor, visual motor problem solving, speech and language, social/emotional, and adaptive skills (Gerber et al. 2011).
Gross motor skills are the most obvious to recognize because they involve crawling, walking, running, and throwing. 242Early motor skills are about performing basic body control tasks, starting with first maintaining a head position, then moving the trunk, followed by moving the whole body in ever more skillful ways. Besides significant delays in gross motor skills, any physical findings of abnormal reflexes, asymmetric muscle tone, or being too loose or too tight in overall muscle tone are other gross motor abnormalities that should be noted.
Visual motor problem solving describes a child’s physical interactions with the world. Infants begin by visually tracking and following people or objects, then reaching for and manipulating objects, and later acquire the ability to draw and to write. These fine motor skills (using one’s hands and fingers) rely on visual input and generally progress at a slower pace than gross motor skills. If the development of these milestones is delayed, it may be because of impairments in sensory, cognitive, or motor abilities.
Speech and language skills are essential for social interactions and academic success. To be able to communicate, a person first has to be able to receive input (process what is seen and heard), pragmatically understand the meaning of that input, then generate an expression of his thoughts (translate thoughts into words, then express fluently). Delays in expressive language milestones may be more apparent than receptive language delays, which may be more subtle but when present may worsen an expressive language impairment.
Social/emotional skills are the core elements of psychiatric functioning. Infants are essentially born with three emotions (anger, joy, and fear), and the circumstances to elicit those feelings become increasingly complex as they grow up. Social skill development is interactive and thus reliant on the presence of a responsive caregiver. A child’s temperamental traits, such as having a high- or low-intensity disposition, influence how he responds to routine activities, which influences how his caregivers respond. Developing shared joint attention with another person by approximately age 1 year is a key social milestone. Normal social and emotional development relies on many other skills but is most closely linked with speech and language skills.
Adaptive skills initially involve learning to feed oneself, dress oneself, and use the bathroom. For older children, adaptive skills involve self-direction, self-protection, and the ability to function independently in a school setting. Adaptive skills use both motor and cognitive abilities and thus are 243not a truly independent category of development. When you evaluate for the presence of an intellectual disability, adaptive milestones need to be investigated because the intellectual disability diagnosis should not be made without demonstrable impairments in adaptive functioning. Standardized intelligence testing is no longer considered the sole basis for diagnosing intellectual disability.
A child may acquire all of his skills in the usual sequence but at a slower rate (a delay), may acquire his skills at differential rates in different areas (a dissociation), or may achieve milestones out of the usual order of acquisition (a deviation). Growth and development will follow recognizable patterns, but it is not an exact script. For instance, a perfectly healthy child might never crawl, instead scooting or rolling to move around before taking his first steps. The task of a pediatric health care practitioner is to always consider what would constitute normal-range development (Table 12–1). Then he can, variously, alert caregivers if a child is not keeping pace with development and thus needs developmental assistance services, reassure worried caregivers when a child is keeping pace with the normal range of development, or simply better understand how a child engages his environment.
Determining when a child’s delayed milestone acquisition would indicate the need for further evaluations or an intervention can be a challenging decision when developmental delays are subtle. To guide your decision, Table 12–2 contains a list of specific cognitive, motor, and social/emotional traits at different ages that suggest a need to refer for specialized developmental assessments.
244TABLE 12–1. Selected normal-range developmental milestones
Age |
Gross motor |
Visual motor |
Speech and language |
Social/emotional |
Adaptive skills |
2 months |
Has good head control; lifts chest up in prone |
Tracks with eyes; holds own hands |
Is alert to voice; makes vowel-like noises |
Shows reciprocal smiling; recognizes parents |
Opens mouth at sight of breast or bottle |
4 months |
Leans on wrists in prone; rolls prone to supine |
Has hands usually open; reaches persistently |
Orients self to voice; vocalizes in response |
Parent’s voice stops cry; smiles on own |
Briefly holds breast or bottle |
6 months |
Briefly sits alone; pivots in prone |
Rakes item to pick up; transfers hand to hand |
Stops briefly for “no”; babbles consonants |
Has stranger anxiety; visually identifies parent |
Feeds self crackers; stares at new faces |
9 months |
Pulls to stand; cruises; comes to sit |
Has immature pincer; looks for fallen toy |
Imitates sounds; enjoys gesture games |
Follows a point; experiences separation anxiety |
Bites, chews cookie; looks for fallen item |
12 months |
Stands well; takes independent steps |
Has fine pincer grasp; scribbles if shown |
Follows one-step request; uses gestures |
Points to get object; shows shared interest |
Finger feeds items; takes off a hat |
24518 months |
Runs well; stands for ball throw |
Scribbles on own; makes 3-cube tower |
Points to self; uses 10–25 words |
Can show shame; does pretend play |
Gets onto chair; removes garment |
2 years |
Throws overhand; kicks ball |
Makes 4-cube train; imitates circle and line |
Uses two-word sentences; understands me and you |
Does parallel play; begins defiance |
Opens doorknob; pulls off pants |
3 years |
Walks up stairs; catches ball |
Copies a circle; recognizes a color |
Uses three-word sentences; names body parts |
Engages in imaginative play; can share on own |
Begins independent eating; unbuttons item |
4 years |
Balances on one foot 4 seconds; can broad jump 1 foot |
Writes part of name; copies a square |
Follows three-step request; tells stories |
Group play; has preferred friend |
Toilets self alone; uses fork well |
5 years |
Walks down stairs; jumps backward |
Cuts with scissors; uses a paper clip |
Responds to “why?”; likes rhyming words |
Apologizes for error; has group of friends |
Dresses and bathes independently |
Source. Adapted from Gerber et al. 2010a, 2010b, 2011.
246TABLE 12–2. Developmental red flags that should trigger specialized assessments
Age |
Cognitive |
Motor |
Social/emotional |
4 months |
Lack of visual tracking; no laugh or vocalizations |
Lack of seated head control; inability to grasp toy |
Does not watch/track people; does not have a smile response |
6 months |
Failure to turn toward sound or voice |
Does not roll or move on the floor |
Lack of spontaneous smile |
9 months |
Lack of babbling consonants |
Inability to sit |
Cannot reciprocate vocalizations or facial expressions |
1 year |
Cannot respond to own name; cannot imitate sounds |
Cannot hold two objects and hit them together; cannot pull to a stand |
Cannot reciprocate hand gestures; will not share joint attention (“Look at...”) |
1.5 years |
Cannot point to a named object; cannot use any words |
Unable to walk independently |
Lack of any speaking/gesture combinations |
2 years |
Speech much less than 50% understandable |
Cannot walk on steps with assistance; cannot kick a ball |
Cannot use a meaningful two-word phrase; lack of empathy (looking sad if a child cries) |
2473 years |
Cannot use a three-word sentence; speech only 50% understandable |
Cannot jump; cannot throw object overhand |
Never imitates adult activities; cannot do parallel play |
4 years |
Speech less than 75% understandable; cannot identify self or details in pictures |
Cannot balance on one foot for 3 seconds; cannot copy a circle |
Lack of imaginative play; cannot hypothesize another’s thoughts |
Source. Adapted from Gerber et al. 2010a, 2010b, 2011; McLaughlin 2011. 248