A new UK study has shown how mums have a soft spot for sons, as they are found to be more critical of their daughters than their sons.
According to the survey conducted by the parenting website Netmums, a majority of mums view girls more negatively - and are much stricter with them - than boys.
Despite 48 per cent deeming it wrong to do so, almost nine mums in ten admitted treating girls and boys differently, reports the Scotsman.
Psychological experts said this could explain why women tended to be more self-critical than men as adults.
The survey found that 55 per cent of mothers felt they had a stronger bond with their sons than with their daughters.
The research showed the mothers profiled their children according to gender, with boys being labelled with far more positive traits than their sisters.
In the study, it was found that boys are seen as "funny", "cheeky", "playful" and "loving" whereas girls are viewed as "stroppy", "argumentative", "eager to please" and "serious".
The bias held true even for mothers who only had daughters and the survey indicated that the negative perceptions had a direct impact on the way parents treated their children.
More than one in five questioned let their sons get away with more and turned a blind eye to behaviour in boys for which they would reprimand their girls.