There is known to be a strong genetic component to autism. Researchers often use studies of twins to investigate the genetic links to illnesses and a team of researchers from the Kennedy Krieger Institute in Baltimore studied 277 pairs of twins in which at least one of the twins had autism. They found that when one identical twin developed autism 88% of their twins also developed it compared to only 31% in non-identical twins. As well as being more likely to both develop autism the identical twins also developed similar forms of autism too. They had similar levels of day-to-day functioning and similar risks of intellectual impairment.