'[4] The frequency of shared parenting versus sole custody varies across countries, being most common in Scandinavia.
[5][6][7] In a comparative survey of 34 western countries conducted from 2005 to 2006, the proportion of children aged 11 to 15 living in a shared parenting arrangement versus sole custody was highest in Sweden (17%), followed by Iceland (11%), Belgium (11%), Denmark (10%), Italy (9%) and Norway (9%).
These finding holds for all age groups, whether the parents have an amicable or high-conflict relationship, and after adjusting for socio-economic variables.
In a large cross-sectional study comparing over 50,000 children, ages 12 and 15, living in either a shared or sole custody arrangement, Dr. Malin Bergström found that children with shared parenting had better outcomes for physical health, psychological well-being, moods and emotions, self-perception, autonomy, parental relations, material outcomes, peer relations, school satisfaction and social acceptance.
[11] Using data from the same cross-sectional survey, Bergström did a follow-up study focusing on psychosomatic problems of concentration, sleeping, headaches, stomach aches, tenseness, lack of appetite, sadness and dizziness.
They found that both boys and girls did better living in a shared parenting versus sole custody arrangement.
In fact, some argue that shared parenting is one critical component in the efforts to reduce the gender pay gap.
[18] In addition, shared parenting can help children develop better problem solving and communication skills, while also providing greater stability through consistent schedules and routines.
[19] Early criticism of shared parenting was based upon the assumptions (i) that children need one single primary attachment figure to bond with, (ii) that child development suffer from frequent moves back and forth between two households, and (iii) that one should not disrupt the status quo.
Couples at high risk for interpersonal violence also do not make good shared parenting candidates.
In Scandinavian countries, such as Iceland, it is commonly viewed as a gender equity issue with strong support from women's organizations.
As yet another contrast, in countries like Turkey and Iran, it is often seen as a women's right issue, as sole custody is commonly awarded to the father.