Response to gaze is reckoned to be a good measure of the development of theory of mind in human children.

ECONOMIST: Now, it seems, even the bird-brained have theories of mind

There is a theory that merely having a lot of children can increase the chances of future pregnancies.

BBC: NEWS | Health | Genes help women over 45 conceive

The theory that public smoking bans cut the number of children born prematurely has been strengthened by new research.

BBC: Smoking ban 'cuts premature births'

Mr Stannard a retired professor of physics at the Open University, as well as the author of a series of children's books on quantum theory is a believer.

ECONOMIST: A counterblast to Stephen Hawking

But across the population the number of children born with disorders is likely to increase if this theory holds true.

BBC: Older dads linked to rise in genetic disorder

Only 41% thought the Tiger mom theory parenting method was flawed and just 18% said it robbed children of their childhood.

FORBES: Most Chinese Really Are "Tiger Moms", Survey Says

In contrast, only children, who in theory share many characteristics with first borns, reported the highest instance of taking financial risks at least sometimes, 39 percent, such as borrowing for short-term investments, or investing in risky ventures.

FORBES: One More Reason to Blame Mom and Dad for Your Money Habits?

The theory behind outdoor napping is that children exposed to fresh air, whether in summer or the depths of winter, are less likely to catch coughs and colds - and that spending a whole day in one room with 30 other children does them no good at all.

BBC: The babies who nap in sub-zero temperatures