Growth and Development
Frameworks examiners love
Growth is quantitative (weight, length or height, head circumference plotted on age- and sex-specific charts); development is qualitative and follows predictable sequences: cephalocaudal (head to toe), proximodistal (center outward), and gross motor before fine motor. Learn theorists with their age bands. Piaget: sensorimotor birth to 2 years, preoperational 2-7, concrete operational 7-11, formal operational 11 and up. Erikson: trust vs mistrust in infancy, autonomy vs shame and doubt 1-3, initiative vs guilt 3-6, industry vs inferior 6-12, identity vs role confusion in adolescence.
Milestones and growth math
Term infants regain birth weight by about 2 weeks, double it by 4-5 months, and triple it by 12 months; length rises roughly 50% in the first year. The anterior fontanel closes between about 9 and 18 months, the posterior by 6-8 weeks. Expect walking alone around 12-15 months, two-word phrases by 18-24 months, parallel play in toddlers, and associative or cooperative play in preschoolers.
Screening and red flags
Use validated tools such as the ASQ and M-CHAT (autism screening at 18 and 24 months) and refer early. Loss of an achieved milestone, persistent asymmetry, or no response to sound or voice always warrants evaluation. Acute illness, hospitalization, and stress cause temporary regression: reassure and recheck, but never dismiss it.
Traps
Questions swap theorists, shift milestones by six months, or present a precocious skill as the expected norm. Another trap: labeling a short child as delayed when the child has constitutional growth delay with normal growth velocity.
Rule of thumb
Milestones are ranges, not deadlines, but loss of any skill is abnormal until proven otherwise.