Deaf children whose parents do not use sign language developed a gestural communication system called ________.

Researchers have found that if one identical (monozygotic) twin suffers from schizophrenia, the other twin has a 50% chance of developing that condition. In fraternal (dizygotic) twins, however,

if one twin has the condition than the other a 27% chance of developing the disorder. These results provide evidence that there may be a strong __________ component to schizophrenia. a. environmental b. heritability c. diathesis d. chemical

What is learning that has taken place but is not demonstrated called?

a. observational learning b. latent learning c. classical conditioning d. instinctive drift