So I think all of us are aware of the fact that female and male same sex friendships are different.The research also proves this as well.

A friendship questionnaire previously used in the United States of America was administered to compare results of the two cultures. Findings from this study support American research suggesting that women are more intimate and emotional in their same-sex friendships than men, and tend to place a higher value on these friendships than men do. In accordance with findings of the American sample, New Zealand women emphasized talking, emotional sharing, and discussing personal problems with their same-sex friends, and men showed an emphasis on sharing activities and doing things with their men friends. Differences between the American and New Zealand samples were shown for men in the number of friends and the intimacy levels of these friendships. New Zealand men preferred numerous but less intimate same-sex friends, while women (as in the United States) showed a preference for a few, close, intimate same-sex friends. Men, in contrast to women, derived emotional support and therapeutic value more from their opposite-sex relationships than their same-sex friendships. Finally, more men than women stated they would not cancel an engagement with an opposite-sex friend in order to go out with a same-sex friend.

So I think we can all agree that male and female same sex friendships are different,but one thing I think people disagree on is what causes these difference.Some people in this sub will try to say that socialization is 100% to blame,others will claim it's just a part of our biological programming.I agree more with the later argument.

Let's look at things from an evoluntionary perspective.In hunter-gathers societies men would usually be the ones to hunt animals for food,and women would gather food and take care of children.Women would even get help with childcare from other women as well.These differences in gender roles may be responsible for creating evolved differences in male and female friendships.

There was actually research done on sex differences in the effects of the bonding hormone oxytocin,and this is what they found.

In addition to the main effect of OT on understanding social relationship, this study is the first to show a gender-specific behavioral effect of OT: while women showed increased ability to recognize familial relationships, men demonstrated improved identification of competitive relationships following the administration of OT. Interestingly, OT had only mild non-significant effect for the recognition of intimate relationships, in both women and men. This surprising finding might reflect the difficulty of this particular relationship category, as accuracy levels for both men and women were significantly lower than the other categories. Similarly to our results, intimacy recognition in this task was previously shown to be the most difficult of all categories for both sexes (Archer et al., 1993). The sex differences in the oxytocinergic system of humans reported here are consistent with the recent report of Domes et al. (2010), which showed a different neural activation pattern of OT in women, as opposed to the previously reported activation found in men. In their study, women who received OT exhibited increased amygdalar activation in response to fearful facial expressions, while men typically displayed the opposite pattern of decreased activation of the amygdala under the same conditions. As in the present study, Domes et al.’s results suggest a differential effect of OT on both sexes in the context of processing social behavior. Likewise, Gordon et al. (2010) recently reported a differential behavioral effect of OT in mothers and fathers. In their study, they report that maternal OT levels correlate with affectionate behavior toward the offspring, as expressed in vocalizations and facial expressions, while paternal OT levels correlated with stimulatory behavior, including physical contact and tactile stimulation (Gordon et al., 2010). Similarly to the present study’s findings, these results demonstrate that gender differences in OT may be evident in different categories of social behaviors. Furthermore, the gender-specific outcome reported here points to some stereotypical characteristics of the effect that intranasal administration of OT has on individuals’ social perception. These results coincide with the biosocial origin theory presented by Wood and Eagly (2002), suggesting that biological factors, mainly hormonal, together with social and cultural factors, act to influence behavioral sex differences. These differences are expressed in women’s pro-social behavioral tendencies, by which they tend to be more communal and familial in their behavior, whereas men are more inclined to be agentic, that is, masterful, competitive and striving to improve their social status.

I think that social norms regarding male friendships stem from our biological programming,and that they may help reinforce these innate sex differences in same sex friendships,but there not the root cause of these difference.