Persistence of primate hand preference despite initial training to the contrary

Area of Science:

• Primatology
• Neuroscience
• Behavioral Science

Background:

• Hand preference, or lateralization, is a fundamental trait observed across many species.
• Understanding the factors influencing the development and expression of hand preference is crucial for behavioral studies.

Purpose of the Study:

• To investigate whether stumptail monkeys (Macaca arctoides) exhibit a predisposition to choose a specific hand when initiating a novel task.
• To determine if initial hand choice, regardless of reward, influences subsequent task performance.

Main Methods:

• Forty-six stumptail monkeys were assessed for hand preference using a simple reaching task.
• The initial reaches made with the first-chosen hand were unrewarded.
• Subsequent reaches, including the first with the opposite hand, were rewarded to calculate overall preference.

Main Results:

• A significant majority of monkeys continued to favor the hand initially selected for the task, even though it was unrewarded.
• This preference persisted over the hand that eventually received rewards.

Conclusions:

• Stumptail monkeys demonstrate a predisposition to utilize their preferred hand when engaging with a new task.
• This finding suggests that established motor biases may play a significant role in the initiation of novel motor behaviors.