The Second-Agent Effect: Communicative Gestures Increase the Likelihood of Perceiving a Second Agent
2011

Communicative Gestures Help Us See Other People

Sample size: 23 publication 10 minutes Evidence: moderate

Author Information

Author(s): Valeria Manera, Marco Del Giudice, Bruno G. Bara, Karl Verfaillie, Cristina Becchio

Primary Institution: University of Torino

Hypothesis

Does observing communicative gestures influence the perception of a second agent in visual tasks?

Conclusion

The study found that communicative gestures increase the likelihood of perceiving a second agent, even when that agent is not present.

Supporting Evidence

  • Participants were better at detecting a second agent when a communicative gesture was present.
  • The lowered response criterion in the Communicative condition suggests a perceptual effect.
  • Results were replicated in a second experiment with different conditions.
  • Participants reported seeing a human figure even when it was not present.

Takeaway

When we see someone making a gesture, we might think there's another person there, even if there isn't. It's like our brain is trying to guess what's happening.

Methodology

Participants viewed point-light displays of two agents and performed a yes-no task to detect the presence of a second agent.

Potential Biases

Participants may have had a response bias towards indicating the presence of a second agent.

Limitations

The study's findings may not generalize to all types of gestures or contexts outside the experimental setup.

Participant Demographics

23 undergraduate and graduate students from the University of Turin, 8 male and 15 female, mean age 26.5 years.

Statistical Information

P-Value

0.005

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pone.0022650

Want to read the original?

Access the complete publication on the publisher's website

View Original Publication