A young girl’s or boy’s need for nurturance and affection is natural. When their parents are incapable of being the loving and mature adults they deserve to help them grow up into a fully functioning adult, problems occur. When incest enters the equation, psychological devastation disrupts their development.
Children (and yes, under 18-years-old, they are still children) don’t want sex with their fathers or mothers. They are coerced and manipulated into believing that molestation is natural and somehow their mother/father is only giving them what they want.
Too often, the situation the child finds him/herself in is an isolating environment with too many secrets. They search for love and nurturance within this framework, but end up totally confused and overwhelmed. Since they believe they are the cause of their incestuous behavior, their self-esteem is very low. Many times they unconsciously use dissociation as a coping mechanism to deal with their trauma.
Expressions of pain, fear, and extreme anxiety present themselves physically with complaints such as gastrointestinal pains and very poor sleep habits.
All too often, the result is reversed. The parents grow to depend on their daughter/son to maintain the stability of the household and keep it intact. Their role becomes that of the rescuer, whether they like it or not. The father exerts his anger or pouts like a child to manipulate his daughter into taking care of him. The mother is verbally abusive and condescending, thus pushing the daughter toward her father or brother for sustenance.
This triangle of deceit is all at the son’s/daughter’s expense and has devastating consequences for their wellbeing.
 Patricia W. Crigler, Insight in the Military Family, in Kaslow et al, The Military Family, pp. 98-124