A case study: Twins in Volley

Twins in general, twins in sport in particular are one of my interests as hobby. I try to follow twins in sports.
Since I am relatively new to volleyball (since 2010-2011), I don't know twin volley-ers other than Gozde-Ozge twin.

This is a a little philosophical, a little socialogical, a little scientific, a little fun, a little bla bla topic where we can talk about twins to question somethings also in the life.

First question comes to our minds in the life is "talent is an in born thing or a gained thing in the life."
To try to answer such questions which may have more than one answer is to reduce the dimension, to reduce number of factors and existence of "twins" gives this chance to us.

Yes, usually, appearences of twins are same or almost same. What about their talents? Their in-born talents too are same? Their gained talents in the life too are same? Or, are we outside people to them the ones who are making difference between them? And, such questions.

As a good example, lets take Gozde-Ozge twins.
Their physical appearences and shapes are still almost same (so, one less factor in understanding differences.)
They have spent more or less same sport efforts (one more less factor to reduce reasons in differences in their later lifes.)
They are at same volley level more or less (one more less factor in comparing and reasoning differences.)

But, we people are saying Gozde is very good player while Ozge is not..
So, what is underlying thing in our this judgement? Are we fair or are we the ones in their environment who make real differences in the life or differences are created virtually in our minds? If talent is an inborn thing and since it is almost same in twins, then, talent we often mention is a gained thing mostly and this means surrounding things, environment, we people are the ones who cause differences between twins in particular and people in general.

How do you see their talent differences, successes etc of Gozde-Ozge twins? Or, mention some other twin volley-ers if they are some different than G-O twins.

If you could say somethings about their performances, it could be better.

For example, can you say one of twins is great and the other is low quality volley-er. Just comparing each others, without comparing any other volleyballers.

For example, as I said before, people say "Gozde is (ok, maybe, not great, though, debatable, but) a very good player while same words aren't said for Ozge by same people who even say she is a low quality player.
I find this interesting really.