I think it is relavant...if you look at the toys that girls are more prone to get as opposed to boys, I think the "pretty" or "Beauty" factor probably plays into it a great deal...at least for the typical girl vs. boy. You have exceptions to every rule.
Some time ago, I read an article about an horrible accident that turned into an gender psychology observation.
a couple had just had twin boys. The hospital uses some scary cauterizing tool to de-tip them (for the life of me, can't think of the bloody word).
There was an accident and one boy got a full burn. The solution was to finish the job and call him a girl because they did not think that genetics mattered, only environment. This was all disclosed to the family (not some super secret I thought I had 2 boys tale).
What was discovered quite readily, was that you can dress a boy up in girls clothes, give them girl toys, call them a girl, chop off their parts, and you will get a confused kid who wants to do boy things.
The problem did ultimately get resolved (science and surgery caught up) as the family could tell the plan wasn't working.
whether its genetics or horomones, it is biology. Boys act like boys. Girls act like girls. Barring the exceptions, the generalizations are accurate.
Girls like flowers and pretty things. Boys not so much.
More males care about functionality than they do over form. You can tell by their living conditions, cabling of their TV and x-box, general appearance, etc.
More females care about form than they do over functionality. You can tell by the clothes they where, the concern they have over curtains, paint, etc.
Sure, there's cross-over, and it doesn't mean they're gay. But as a general rule or summary of the majority, girls like pretty. Boys don't care if the lego blocks match in color, unless they have enough to do so.