For the test, researchers videotaped participants during one-on-one interview sessions. Two types of behaviors were looked for in these tapes—the first being disengagement behaviors such as fidgeting and/or doodling, and the second being, engagement behaviors such as head nodding, laughing, and eye contact.
The results showed that nonverbal cues can give away a person's SES. Volunteers whose parents were from upper SES backgrounds displayed more disengagement-related behaviors compared to participants from lower SES backgrounds.
In addition, when a separate group of observers were given the clips to watch, they could correctly identify the SES class of the test subjects.