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There are (at least) two ways epigenetic traits are inherited. The important background in both cases is gene expression: there is a misconception that genes are for this or that, where the reality is that most traits come from an overlap of several genes expressing themselves in different ratios. As a simple example, consider two varieties of bird of the ...


9

Monozygotic twin studies are the general course of action for this kind of question. Genetic and environmental influences on multiple dimensions of religiosity: a twin study concludes there is a genetic component. A complete approach for these kind of studies is to take twins that have been separated to different households from birth and compare them to ...


8

Heritability estimates of Extraversion (and other Big 5 factors) The introduction section of Loehlin et al (1998) provides a narrative review of heritability estimates of big 5 personality traits (i.e., one of which is extraversion). A brief extract gives a flavour of some of the research that has been conducted: A recent heritability analysis of the ...


7

To learn about other twins reared apart, investigate the earlier Minnesota Study of Twins Reared Apart and the ongoing Minnesota Twin Family Study. To pique your curiosity: Jim Lewis and Jim Springer stand out in the Minnesota Study of Twins Reared Apart because some of their two histories were strikingly identical; several notable examples: 1st wife: "...


7

First of all, asymmetries in apparently symmetric creatures (of which most are) are actually quite typical. However, in most cases of hand dominance, there is no population-wide hand dominance. In other words, the population is split 50/50 between left and right handers. In humans, however, a lack of hand dominance is often associated with cognitive ...


6

psychological sequelae might be a word you're looking for if you forgive that it's somehow still neurobiological; it is however, not genetic or developmental or something somebody was born with: Chronic kidney disease, for example, is sometimes a sequela of diabetes, and neck pain is a common sequela of whiplash or other trauma to the cervical vertebrae. ...


6

As I alluded in the comments, I think your question is underpinned by a more fundamental worry of the "best level of description" for psychological phenomena. If you a reductionist then you believe that all of psychology is best explained in terms of the activity of neurons (or systems of neurons if you are of the system perspective; note that some do not ...


6

Short answer People with above-normal hearing exist. Background Normal hearing was defined as the average of a group of young healthy individuals. These normal hearing levels are currently used to express acoustic sensitivities. One commonly used way is to use decibels relative to this normal hearing level (dB NH). This scale is used in audiograms (Schnupp ...


6

In my mind there are two main explanations of this kind of instinct behaviours. The first one is rooted in evolution. There are many examples of human innate behaviours which we can't explain e.g. when we see a lace or tape on the street we automatically jump and feel scared. Although we live in big city our brain associates the lace with a snake. It is an ...


6

Short answer: It might be genetic. Human sexual behaviour, especially where stigma and taboos are involved, is notoriously difficult to study, so the real answer is that we just don't know. However, some evidence suggests that genetic factors may be at play: A 2008 study compared 112 male-to-female transsexuals ... with 258 cisgender male controls. ...


5

The psychology-spot article mostly links to researches done on mice. Only three links are about human genetics. One is philosophical in nature, other two deal with mental retardation. This study says that: "X chromosome contains a significantly higher number of genes that, when mutated, cause mental impairment". We know that boys get their X chromosome ...


5

You could start by reading "Intelligence: Knowns and Unknowns". This is a consensus article based on many of the world's leading researchers on intelligence. Empirical research suggests that variations in intelligence is largely hereditary. Specifically estimates of heritability of intelligence at adulthood based on monozygotic twin samples who were reared ...


5

Exactly like you, I would like to begin by saying that I have no animosity nor prejudice against anyone. What I am saying below is not meant to be offensive to anyone, it is just an honest account of what the data in my region says. You wrote: "I can only think of 2 possible solutions ... either a difference in psychological predisposition between the ...


4

Yes, phobias appear to be partly hereditary. This encompasses both genetic and environmental factors. Kendler et al. (1999) review some work in this area: We have previously reported, from a population-based sample of female twins, that the liability to agoraphobia, social phobia and animal phobia was modestly infuenced by genetic factors with ...


4

First off, I think monogamy is a socially and culturally determined construct in man. In the animal world both monogamy and polygamy are encountered. Monogamy increases the chance of the survival of individual offspring, as dad can help raising the offspring and can defend the family. This increases fitness. On the on the other hand, polygamy increases ...


3

Yes, there is almost certainly a genetic overlap between schizophrenia and OCD. Quantifying the overlap in variation requires genotyping a large number of individuals, and a lot of this cross-disorder work is done by consortia. The Cross-Disorder Group of the Psychiatric Genomics Consortium estimated the genetic correlation due to common polymorphisms ...


3

The approach you would take will depend upon your level of analysis. For instance, one could choose to model an entire individual's behaviour (i.e. with heuristic models), the activity of neural circuits, the activity of a subset of neural populations, etc. By your question including traits such as "impulsivity," I will assume that you are looking to model ...


3

The statement 50% of happiness is determined by genetics is presumably talking about heritability estimates. It is probably talking about the percentage of variance explained by genetics. These estimates are commonly estimated using twin studies. For example, you administer a survey to people that ask a bunch of questions about how happy they feel. There ...


3

I hope the few sources below answer your question. I strongly recommend you read actual sources as opposed to the parts I have quoted. I don't know much about this topic so I did not attempt to translate anything in laymen terms, since I might have distorted or misinterpreted information in the process. However, the three sources below are one of the best-...


3

Have any studies been done on the inheritability of different mental abilities such as short-term-memory, long term memory and so on. One of the most replicated findings of behavioral genetics is that all psychological traits show significant and substantial genetic influence, however not 100% genetic influence (Plomin et al, 2016). So yes, short term ...


2

In addition to MariaAnt's good contribution, let me take another angle. You wrote: Studies comparing identical and fraternal twins, or occasionally identical twins reared apart have mostly concluded that there is a pretty high heritability of IQ. These studies, in particular the identical twins reared apart studies, imply that someone with the same genes ...


2

The Wikipedia article seems to provide a summary of this information with links to the primary literature http://en.wikipedia.org/wiki/Causes_of_schizophrenia#Genetics Concordance rates between monozygotic twins vary in different studies, approximately 50%; whereas dizygotic twins was 17%. Some twin studies (Koskenvuo et al; Hoeffer et al) have found ...


2

This is my own conjecture: I would think a Nature/neurobiological/genetic disorder would be classified as some sort of "Structural Disorder." Maybe the Nurture side would be something like "Processing Disorder"? (this is assuming we're talking maladaptive effects) Is our science even to a point where we can differentiate between a neurobiological ...


2

The following comes from my research experience using fMRI to study the human visual system. Overall, peoples brains are similar to each other on higher scales, and become very different from each other as the scale becomes smaller. Differences between different people start with brain size and sulci patterns. Also male and female brain anatomies will be ...


2

http://www.theguardian.com/world/2007/dec/12/japan.justinmccurry Here they talk about scientist who shut down fear of cat in mice behavior. After genetic engineering the mouse isn't afraid of the cat smell. The conclusion of this study is that fear (at least in this case) is not learned through experience, but a consequence of genetic evolution. In the end, ...


2

Predisposition to anxiety can be inherited: Genetics and family history (e.g., parental anxiety) may predispose an individual for an increased risk of an anxiety disorder, but generally external stimuli will trigger its onset or exacerbation. Genetics accounts for about 43% variance in panic disorder and 28% in generalized anxiety disorder. ...


2

Epigenetics is the study of changes in gene function, from parent to offspring, that do not involve changes in the DNA sequence. (Source: Wikipedia) In the original sense of this definition, epigenetics referred to all molecular pathways modulating the expression of a genotype into a particular phenotype. Over the following years, with the rapid growth of ...


2

It seems likely that some percentage of twin studies would fail to account for all the systematic environmental variables that connect their twins. In this case, the effects of these variables would still cause a correlation, which would be attributed to heritability. "A second look at twin studies" by Lea Winerman discusses examples of these types of ...


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