against

• the different hormones in men and women may play a role, oestrogen underlies caring behaviour, which may make women biologically more suited to forming attachments,
• there are cultural/social expectations that view child rearing as stereotypically feminine, this may deter males taking on a childrearing role, even if they want to.
• Schaffer and emerson (1964) did find that infants usually attach to their mothers first (around 7 months)