Someone with ASD tends not to begin social interactions or respond to other people's attempts to begin a conversation (ie. ignoring the cashier’s attempts at smalltalk when checking out at the grocery store)
Someone with ASD may avoideye contact and rarely use social smiles in social settings, and may not understand gestures, tone of voice or have issues with body posture
Individuals with ASD may stick to routines and find any change from this pattern of behaviour distressing (ie. if a phone call causes them to miss their usual bedtime story, disrupting their bed time routine)
The general population (who don'thaveany relatives with ASD) has a 0.11% risk of developing ASD, but the risk increases to 2.2% if a sibling has a diagnosis (Szatmari,1999)
Genetic deficits, such as 20p13, could run in families and potentially affect neuronal development, leading to impairedempathy (Theory of Mind) or savantbehaviours
Around 60% of those with Fragile X syndrome also meet the diagnostic criteria for ASD, suggesting the FMR1 mutation may be a genetic factor in the development of ASD
Colvert et al (2015) found concordance rates of 77-99% for MZ twins and 22-65% for DZ twins, supporting the theory that increased DNA leads to increased risk of developing ASD
Hallmayer et al (2011) estimated heritability to only be 55%, suggesting other factors account for the remaining 45% of the influence in the development of ASD
Landrigan (2010) suggests there are possible environmental triggers for ASD, such as toxic chemicals and viruses the mother is exposed to while pregnant
There is no difference in amygdala volume during adulthood and teenage between those with and without ASD, but a 6-9% increase in volume is found in those with ASD during childhood