In Autism there are two types of biological explanations that can explain the condition; the genetics explanations and the neurological explanation.
The genetic explanation of Autism explains the importance of inheritance. If there is a family history of autism and mother has a baby after the autistic child is born then the likely chance of having autism is 3-6%. However on the other hand 0.6% is the comparative figure of having autism in general. Folsten and Piven have recorded a 3% concordance rate in sibling; Concordance explains the percentage/likelihood of having autism. Moreover they explain that there is a higher chance of boys having autism than girls.
Evidence most commonly used to prove that genes play a big role in autism; twin case studies are always used. Fraternal dizygotic twins have 50% genetic similarity, whereas identical monozygotic twins have 100% genetic similarity. MZ twins were most likely to get autism. Riveo et al studied 40 twin pairs for autistic symptoms. 23 pairs were MZ - identical and 17 were DZ – non-identical. He then concluded his results to find that 22 out of the 23 MZ twins had a 96% concordance and the DZ had a 23% concordance. This provides strong proof for genetics, as it shows that it plays a big role in autism.
However the disadvantages of using twin studies such as those are that; they are longitudinal and can have a high dropout rate, and since MZ twins are rare compared to DZ twins – the population of MZ are rare which means that generalization cannot be made. Moreover since the twins are both nurtured in the same environment this could mean that nurture can play a bigger role compared to nature, which can potentially suggest that Autism is environmentally influenced and could challenge it being a biological theory.
Furthermore Frith studied chromosomes – 2,7,15,16 and concluded that autism develops due