How has happiness and parenting changed for US couples?
Does having a baby bring more fulfillment to parents? And, if so, how do mothers and fathers see their roles in raising their child?
In recent years more focus has turned to how children affect the lives of their parents, rather than the traditional questions of how parenting affects a child.
Another evolution also is taking place with how mums and dads take on their duties as parents.
The Pew Research Center has collected numerous surveys among US parents to see just how they feel.
According to the reports, all signs point to a convergence of parenting roles but a gender gap still remains.
The BBC's David Botti breaks down the numbers.
Additional images: ThinkStock and Getty Images
21 Feb 2014