What area of the brain is associated with the overproduction of synaptic connections during puberty?

The likelihood that schizophrenia is a polygenic abnormality explains

a. why researchers cannot seem to find one site for a schizophrenic gene b. why there are differences in severity among those with the disorder c. why risk having the disorder increases with the number of affected relatives in the family d. all of these

The concept that genotypes are not the only things that control traits involves the fact that a. dizygotic twins are virtually genetically identical

b. each genotype can produce a variety of phenotypes. c. recessive genes are more commonly expressed than dominant genes. d. the environment has little impact on behavior.