Echolalia as well as ritualistic and self-stimulatory acts are also prevalent. While syndromes of the disorder are well documented and studied, the actual causes of autism are difficult to pinpoint. Initially it was thought that autism was psychogenic, caused by cold and distant mothers. Today, however, biological and genetic factors are more frequently thought to be the basis of autism. This inability to sense that other people's minds are different than one's own causes the deficiencies in social skills and communication.
Genetic studies indicate a higher incidence of autism among siblings and twins.
Neurological studies have also linked autism to abnormal brain wavelengths, underdeveloped cerebellums and epileptic seizures. Because causes of autism are not really known, treatment of the syndrome is also very difficult. The great variety of symptoms and abnormalities in autistics makes it hard to find one effective treatment for a diagnosed autistic individual. Ivar Lovass documented some success with intensive behavioral treatment. But behavioral treatment requires the heavy involvement of both therapists and parents, and reinforcement is difficult because the self-stimulatory behavior of the autistic interferes with the therapy.