are attitudes hereditary?

[cameron marical]

my father tells me how he has a temper so i will have one too. is there actually a science to that statement?are attitudes hereditary?

 

what about past disorders like schyzophrenia? or ocd? are those hereditary?

 

im guessing yes.

 

thanks.

[Paralith]

There is a lot of evidence to suggest that yes, a lot of personality and other behavioral traits have a genetic component, like this twin study:

 

http://www.psych.umn.edu/courses/fall06/yoonh/psy3135/articles/Jang%20et%20al_1996.pdf

 

Understanding how this inheritance works, and what genes are involved, and how environment affects it, is a whole different story, of course.

[iNow]

Adding to what Paralith said, things like attitude are always BOTH genetic and conditioned. Trying to separate nature from nurture is an exercise in futility since the two are never perfectly separate. You can do studies (like the twin study referenced) which help to pull out which factor has a greater impact, however, it's important to always keep in mind that someones personality will always result from a combination of factors... genetics and personal life experiences... heredity and environment.

[habana999]

Adding to what Paralith said, things like attitude are always BOTH genetic and conditioned. Trying to separate nature from nurture is an exercise in futility since the two are never perfectly separate. You can do studies (like the twin study referenced) which help to pull out which factor has a greater impact, however, it's important to always keep in mind that someones personality will always result from a combination of factors... genetics and personal life experiences... heredity and environment.

 

Absolutely iNow, and if you think of a hypothetical case of one sibling who is perhaps a great scholar/business man and the other who is frequently in prison, yet both brought up by the same parents in the same house going to the same school.

But look at the possible differences in life experience between the two... one is loved and cherished and perhaps came along at the 'right moment' therefore producing (through nurture) a child confident and assertive within their peer group. Or the other child who was born at a time in their parent's life when things weren't so good and as a result they grew up awkward and shy and perhaps fell victim to bullying as a result of that. But of course a complete role reversal could happen!

And where genetic recombination is concerned when no two children really are the same. They could literally.... genetically.. be like chalk and cheese.

The possibilities really are endless.

[Mr Skeptic]

my father tells me how he has a temper so i will have one too. is there actually a science to that statement?are attitudes hereditary?

 

what about past disorders like schyzophrenia? or ocd? are those hereditary?

 

im guessing yes.

 

thanks.

 

Only partly hereditary. You are right to expect a somewhat higher probability of being genetically predisposed to have a temper, but you could also have no genetic predisposition toward anger. Remember that you also get genes from your mother, and that genes can be dominant or recessive, so they could have "hidden" genes.

 

Even if you do get the temper genes from your dad, there is always the option to choose to fight it. Eg you could attend anger management course (or read on the web), if you want to get a head start to counter any tendencies you might have.

[cameron marical]

How are genes deemed Dominant or Recessive? What makes them that?

 

I just used anger as an example, i dont actually have anger problems. Though my dad says that he does and i will, i wasnt lying, maybe my mom is the opposite and i get her gene and not my dads.

 

thanks guys.

[Mr Skeptic]

Genes come in homologous pairs. The two will code for roughly the same thing, but can be different. Genes are deemed dominant if having the dominant gene basically makes it as though the recessive gene were not there. Some genes are co-dominant, so that both are visible but to a lesser degree than if you had two of either one. Recessive genes will only be expressed if you have both recessive genes. So if your parents both have a dominant and recessive gene, you couldn't tell that they have the recessive gene, but you have a 25% chance to end up with the recessive trait.

 

http://en.wikipedia.org/wiki/Mendelian_genetics

[cameron marical]

Yes thank you, but what actually makes them dominate? It cant just be that it makes it so the other isnt there, thats what it does, how does it do it?

[Tsuyoiko]

Yes thank you, but what actually makes them dominate? It cant just be that it makes it so the other isnt there, thats what it does, how does it do it?

 

I think I got this right. Genes cause particular traits by coding for particular enzymes. If someone has two copies of the same allele (homozygous) they will exhibit the trait caused by the enzyme that that allele codes for. If someone has two different alleles (heterozygous), one of which is dominant, they will exhibit the trait of the dominant allele because any amount of the enzyme produced by that allele is sufficient to cause the trait.

[Mr Skeptic]

Yes, essentially due to the feedback regulation of most of our stuff, there is no noticeable difference between having two copies and one copy for several genes. Having no copies, on the other hand, makes a huge difference. A gene that behaves like this would be dominant.

[Paralith]

However, it's important to keep in mind that the vast majority of traits do not have simple mendelian inheritance, and this will be especially true of complex traits like behaviors. Traits like these will be determined by many different genes all interacting in complex ways, with a healthy dose of environmental influence mixed in.

[GDG]

Yes thank you, but what actually makes them dominate? It cant just be that it makes it so the other isnt there, thats what it does, how does it do it?

 

In some cases, the recessive gene has a mutation that alters the expression of its protein product. For example, a receptor gene might have a mutation that effectively inserts a "stop" codon early in the protein, so that only a stub is expressed (and probably immediately degraded). Or, the mutation might be in the regulatory region of the gene itself, so that it just does not get transcribed. In such cases, if there is a "normal" allele present, its product will dominate over the "no protein" recessive allele.

 

Also, many proteins have regulatory functions, and work by binding another protein. If the dominant protein binds much better than its recessive counterpart, you will see essentially only the dominant effect.

 

And, of course, you can have "co-dominant" systems, like the ABO blood groups. If you inherit an "A" from one parent, and a "B" from the other parent, you'll be "AB" -- both alleles expressed.

 

Lots of room for complication

[habana999]

Only partly hereditary. You are right to expect a somewhat higher probability of being genetically predisposed to have a temper, but you could also have no genetic predisposition toward anger. Remember that you also get genes from your mother, and that genes can be dominant or recessive, so they could have "hidden" genes.

 

Even if you do get the temper genes from your dad, there is always the option to choose to fight it. Eg you could attend anger management course (or read on the web), if you want to get a head start to counter any tendencies you might have.

 

Studies show that monoamine oxidase (A & B) dysfunction can lead to aggressive and violent behavior as well as depression and substance abuse (all 'behaviours'). These enzymes breaks down chemicals like adrenalin and noradrenalin (epinephrine and norepinephrine) and are what make you 'calm down' after an argument.

Interestingly the genes coding for MOA-A & MOA-B are found on the X chromosome. Perhaps explaining why men are more likely to become involved in activities such as drug abuse and violence. I wonder how many men are in prison because of some sort of 'deficiency' that leads to anti-social behaviour?

[Paralith]

Men still have another X chromosome, and only one X chromosome per cell is active in women anyway. Unless there are some other mechanisms going on (which there may be), men and women probably have the same dosages of MOA.

[habana999]

Men still have another X chromosome, and only one X chromosome per cell is active in women anyway. Unless there are some other mechanisms going on (which there may be), men and women probably have the same dosages of MOA.

 

 

 

Men only have one X chromosome. Yes one X chromosome in a XX cell is inactivated but that inactivated X chromosome varies between cell types. So, I would imagine women are 50% less likely to have dysfunctional MOA the same way they are 50% less likely to be with sex linked 'disorders' like colour blindness. I wasnt saying that men or women had higher/lower 'dosages', just that men would have higher incidence of MOA dysfunction. Just an observation is all.

[Mr Skeptic]

Men still have another X chromosome, and only one X chromosome per cell is active in women anyway. Unless there are some other mechanisms going on (which there may be), men and women probably have the same dosages of MOA.

 

Men have only one X chromosome. Women have two X chromosomes, and one of them is randomly deactivated during early development (called lyonisation), leaving clumps of cells with one or the other X chromosome active. This mosaic is what gives female tortoiseshell cats their unique coat. For many diseases of the X chromosome, this pretty much eliminates the effect on women, since the other X chromosome can cover for it.

[Paralith]

I understand X linked diseases and how they affect men more often. The wording in the post I responded to seemed to be suggesting that all were more aggressive and/or violent than women due to this. Apparently I misunderstood, and I apologize.

[lucaspa]

my father tells me how he has a temper so i will have one too. is there actually a science to that statement?are attitudes hereditary?

 

what about past disorders like schyzophrenia? or ocd? are those hereditary?

 

im guessing yes.

 

I'd be careful about "attitudes". That your father has a particular "attitude" toward sports cars does not mean you will have one. However, since temper is mediated by chemicals in the brain and the level of those chemicals and the magnitude of their action mediated by receptors -- both of which are genetic -- then yes, you could end up with the same type of "temper".

 

The Nov. 7, 2008 issue of Science has a special section "Genetics and Behavior". I've attached the PDF file of the general overview to the post. Those interested should find it helpful.

Parsing the Genetics of Behavior.pdf