Final answer:
Being first born is not typically considered a risk factor for child abuse, whereas factors like substance abuse by parents and social isolation are known risk factors.
Step-by-step explanation:
The question asks which of the following is not a risk factor for abuse among children: 1) colic, 2) developmental delay, 3) special medical needs, 4) first born, 5) physical disability. Among the listed options, being first born is not generally considered a risk factor for child abuse. Risk factors for abuse in children include being raised by substance abusers, which can lead to a higher risk of physical abuse and neglect, as well as social isolation, depression, low parental education, and a history of being mistreated as a child. Special medical needs, developmental delay, and physical disability may increase the stress on caregivers, potentially leading to a higher risk of abuse, while colic, a condition often seen in infants, can increase frustration and stress for parents but is not itself a risk factor for abuse.