Eugenicists were interested in various human disabilities, which they thought would give evidence to support theories of inherited characteristics. Though the performers in circus "freak shows" were intended as "curiosities," eugenicists interpreted their disabilities as examples of degenerate heredity. They thought such people should be sterilized or prevented from marrying.
Field workers from the Eugenics Record Office visited nearby Coney Island, where circus and sideshow acts provided potential data for human hereditary studies. They often scribbled notes and pedigrees on "calling cards" provided by the acts.
The circus cards show a number of physical conditions, including several types of tall and short stature. Hereditary giants show normal body proportions, but giants with pituitary tumors have abnormal bone growth of the face and limbs called acromegaly. Pituitary midgets have normal body proportions, but midgets with achondroplasia have disproportionately short limbs. Other photos show morbid obesity, hypertrichosis (excess face and body hair), phocomelia (shortened limbs), albinism (lack of pigment in skin, hair, and eyes), and icthyosis (elephant-like skin).
Today it is considered unethical for circuses to put people with disabilities on display purely as curiosities. However, clowns and other circus performers may have short/tall stature, hypertrichosis, or other unique features.