In 2011, social scientists conducted a study that looked at post-separation parenting arrangements for infants and toddlers. This study examined the impact of child care arrangements on infants under the age of two, children ages two to three, and four to five year olds. The study focused on patterns of care as rare if any overnights, overnights of at least once per month but less than once per week, and at least once per week.
The study looked at variables such as parental warmth with the child, parental hostility or anger with the child, levels of disagreement and consultation between parents, level of anger toward the other parent, how well the parents related to one another, and satisfaction with the children’s current living arrangements.
This study found that for children under three, spending one or more nights per week with the non-residential parent was associated with greater irritability, difficulty with being soothed, heightened separation anxiety, lower persistence at tasks, more wheezing, more eating problems, and more aggressive behavior towards the parents. Additionally, infants with one or more overnights with fathers showed higher rates of irritability and vigilance.
In toddlers age two to three, the study found that shared care, compared to primary care with no overnights, showed higher rates of separation anxiety, problem behaviors such as hitting and biting, eating problems, and lower persistence in activities and exploration.
In four to five year olds there was no significant negative effect of overnights related to lack of parental warmth or interparental conflict.
Children who lived in shared care for four years had higher hyperactivity and inattention ratings by mothers and children in rigid arrangements also showed more emotional problems than in primary or flexible care arrangements.
Overall, overnights pose a risk even when parents agree to them. However, this risk may be enhanced in the presence of conflict and diminished quality of parenting.