« previous next »

Author Question: What are the problems using twins to determine whether genetic factors cause the onset of psychological....? (Read 1345 times)

camila

  • Hero Member
  • *****
  • Posts: 705
on: Jun 21, 2013
Disorders?

I have been given this as a homework assignment question and I genuinely have no clue why this would be a problem. Any help would be greatly appreciated!


Sandstorm

  • Sr. Member
  • ****
  • Posts: 268
Reply #1 on: Jun 21, 2013
The first thing to consider is whether you are looking at monozygotic (identical) twins or dizygotic (fraternal) twins. The other important fact that must be considered is that genes alone are not usually causative for a disorder which follows the standard rule of phenotype = genotype + environment. In practical terms this means that unless a particular gene effect is completely "penetrant", that is it always causes an effect when it is inherited, twin studies could assign no effect to a particular gene that is only partly penetrant. In the cause of psychological and neuropsychiatric diseases, they are usually not monogenic but the result of numerous genes and environmental influences.


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question

curlz

  • Hero Member
  • *****
  • Posts: 538
Reply #2 on: Jun 21, 2013
The best scientific "twin studies" are those in which identical twins had been separated at birth and raised by completely different families, and had no interaction with one another.

That way, they have exactly the same genes, but completely separate environment.


« previous next »
 

Did you know?

Symptoms of kidney problems include a loss of appetite, back pain (which may be sudden and intense), chills, abdominal pain, fluid retention, nausea, the urge to urinate, vomiting, and fever.

Did you know?

Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.

Did you know?

Opium has influenced much of the world's most popular literature. The following authors were all opium users, of varying degrees: Lewis Carroll, Charles, Dickens, Arthur Conan Doyle, and Oscar Wilde.

Did you know?

Hypertension is a silent killer because it is deadly and has no significant early symptoms. The danger from hypertension is the extra load on the heart, which can lead to hypertensive heart disease and kidney damage. This occurs without any major symptoms until the high blood pressure becomes extreme. Regular blood pressure checks are an important method of catching hypertension before it can kill you.

Did you know?

It is believed that the Incas used anesthesia. Evidence supports the theory that shamans chewed cocoa leaves and drilled holes into the heads of patients (letting evil spirits escape), spitting into the wounds they made. The mixture of cocaine, saliva, and resin numbed the site enough to allow hours of drilling.

Three factors that influence the distribution of Na+ and K+ ions across the neural membrane. Three factors that influence the distribution of Na+ and K+ ions across the neural membrane.
How to solve application problems containing quadratics (Question 1) How to solve application problems containing quadratics (Question 1)
Genetic modification of organisms and DNA recombinant Genetic modification of organisms and DNA recombinant
Concordance Values in Monozygotic and Dizygotic Twins Concordance Values in Monozygotic and Dizygotic Twins
The flow of genetic information The flow of genetic information
The age-of-onset curve for Huntington disease (HD) The age-of-onset curve for Huntington disease (HD)
Video: Blood Test Basics

For a complete list of videos, visit our video library