question

The word hard-wired, dictionary meaning given as involving or achieved by permanently connected circuits designed to perform a specific function. In neuroscience term, it is part of human behaviour, implying a built in nature to human.

Women believed to have the built in nature of helping other people, hence the phrase Women are hard-wired to lend a helping hand.

You will find more helpful reading in the following web site:-

http://cnews.canoe.ca/CNEWS/Rogers/Macleans/2008/02/15/4849200-mac.html

It is mean that women were set to save, help the weak one.