Related Experiment Videos
Handedness for eating in gorillas
Summary
Gorillas exhibit a wide range of hand preferences for reaching, with individual preferences remaining stable over time. This study found no species-wide bias, with roughly equal numbers of left- and right-preferring gorillas.
Area of Science:
- Primate behavior
- Animal cognition
- Neuroscience of handedness
Background:
- Hand preference, or manual asymmetry, is a common trait in primates.
- Understanding the distribution of handedness in non-human primates provides insights into the evolution of lateralization.
Purpose of the Study:
- To investigate the range and stability of hand preference in lowland gorillas (Gorilla gorilla gorilla).
- To determine if there is a population-level bias towards left or right hand preference in this species.
Main Methods:
- Observations of spontaneous food-reaching behaviors in 31 captive lowland gorillas.
- Systematic recording of hand used for reaching across multiple observation sessions per individual.
Main Results:
- A full spectrum of hand preferences was observed, from strong left to strong right.
- Most gorillas displayed intermediate levels of hand preference.
- Individual preferences showed high consistency across different observation periods, indicating stability.
- Approximately half the gorillas were left-preferent, and half were right-preferent, with no significant species bias.
Conclusions:
- Lowland gorillas exhibit diverse and stable hand preferences, similar to other primate species.
- The absence of a population-level bias suggests that lateralization for reaching in gorillas is not strongly skewed.
- These findings contribute to the understanding of motor lateralization and its evolutionary trajectory in great apes.