[Titanscape (OP)]

Separated twins are known to have a lot in common in behaviour. But in all of us how much is from nature and how much from nurture?

[gecko]

id say 80% nurture and 20% nature. most people think theres more nature involved than i do though.

[elegantlywasted]

In an episode of CSI recently (I know high quaility learning) Grissom made a good point, when two people are genetically identical the chances of them having simmilar attributes, voice, handwriting etc. is pretty good, and quite likely has nothing to do with nurture.

[rosy]

I'd have thought voice is likely to be very similar... same sort of default construction of vocal chords etc, although there'd be a correction for accent. I wouldn't necessarily expect the naked ear to pick it up but I should think the cunning software for fourier transforming speech patterns would spot it no problem.

On the other hand, I'd be a lot more sceptical about handwriting, because that is something that is very much taught... I know that when Iwas first at secondary school I could have sorted my classmates exercise books by what primary school they went to just on the handwriting style they'd learnt there.. Rushmere Hall was all pointy, St Margaret's had funny "e"s, etc.

I think there's a lot of discussion of what's nature and what's nurture, and it's all of it random speculation. I've yet to see anyone, anywhere, cite a study I belive in.. not least because how one would carry out such a study without its being ethically a hideously bad idea is a bit of a mystery.
Also, opinions on the whole discussion tend to be depressingly politicised (and I'm as guilty as the next man)... in the absence of evidence people pick what they're most comfortable beleiving in... "it's all nature" for the people who don't want to believe that the current generation are sick/bad because the last generation let them down, "it's all nurture" for the people who want to believe that somewhere out there there's a right answer.