His interest in portraiture led Degas to study carefully the ways in which a person's social stature or form of employment may be revealed by their physiognomy, posture, dress, and other attributes. In his 1879 "Portraits, At the Stock Exchange", he portrayed a group of Jewish businessmen with a hint of anti-Semitism. In 1881 he exhibited two pastels, "Criminal Physiognomies", that depicted juvenile gang members recently convicted of murder in the "Abadie Affair". Degas had attended their trial with sketchbook in hand, and his numerous drawings of the defendants reveal his interest in the atavistic features thought by some 19th-century scientists to be evidence of innate criminality. In his paintings of dancers and laundresses, he reveals their occupations not only by their dress and activities but also by their body type: his ballerinas exhibit an athletic physicality, while his laundresses are heavy and solid.