breathilizer

How large of a role do genetics play on our personalities?

braces_for_impact

Have you read The Blank Slate by Stephen Pinker? It talks much about the role of genetics in society and behavior.

As to the OP, I think more than most people realize.

arcadia

It may be a meaningless question. Personality traits are very vague and difficult to measure. Is that person friendly and outgoing, or does he just seem that way? Because that person seems to scowl a lot, is he a real meany? Is she happy or a Pollyanna? Does she even know the answer to that question?

There are hundreds of researchers out there desperate to tie down these loose ends and further define us as nothing more than the product of our genes.
There are thousands of shrinks advocating the nurture end of the spectrum.

Among the genes that some researchers claim to have discovered are those for shyness and risk-taking. I have grave doubts about the reliability of both the personality metrics and genetic evidence.

While my personal conviction is that very little of our "personality" is genetically determined, I still recall very clearly that each of my children, born of the same parents and in similar circumstances, did vary considerably in some personality traits within the first couple of weeks.

infinity

i tend to believe that all aspects of our personality exist due to a system of bioelectric chemicals, neuron interaction, etc etc. a very natural and scientific method.
i also believe that we all choose who we are. there is nothing about yourself (personality wise) that a person can not choose to change if they *really* want to.
i also think though that our parents makes the tissue that leads to us being formed. their genes make our genes. those genes make our brains. those brains make us. i find it inconceivable that in the formation of our bodies and brains, SOME traits are not given to us.
i don't believe these traits are permanent. but i do think certain *deeply* ingrained ways of thinking may become geneticlly passed to later generations.
i think racism, sexism, religious conviction, etc etc... opinions that can be so deeply founded in a person as to become part of who they are... can be passed to their children in a sort of 'predisposed to that opinion' manner. not that the child will have no choice but to think that way, but that it's sort of just already there... and unless they actively seek to examine it and change it, they never will

Roland98

I'm going to move this up to E/C, since that's the default biology forum.

Donkey_Popsicle

In Pinker's The Blank Slate it is said that about fifty percent of the variance of personality (from some set standard, apparently) is due to genetics, and most of the rest due to the unique environment (peer groups and the like). The Shared environment (being parenting, mainly) has little effect. Perhaps ten percent at most. I'm sure the figures vary somewhat (a quick google reveals a study that claims two-thirds is genetic), but the general view is that genes play quite an important, if not the main role.

Sensei Meela

Two points to make: 1) Norm of Reactions and 2) Evo-Devo.

1) The Norm of Reactions refers to the range of phenotypical expressions a single genotype may have. (For example, cloned grasses grown at low and high altitudes [under the same nutrient and light reigments] display marked differences in height) It highlights a new 'push' in biological thinking towards Gene x Environment interactions.

2) One specific type of GxE interaction, the developmental environment (ie 'womb' for us) is highly influential of the phenotype. Evo-devo expands the 'nature' side of the conflict (with 'nurture') by accounting for the expression of genes through feedback early on in developmental pathways.

In short, your personality seems to be a product of, not just what genes you have, but how they are expressed, into what environment and how they interact (GxE). There is considerable room for variation, even among 'genetically identical' individuals.