Laboratory assessment of temperament and environmental enrichment in rhesus monkey infants (Macaca mulatta)
Mary L Schneider1, Colleen F Moore1, Stephen J Suomi2
1University of Wisconsin-Madison, National Institute of Child Health and Human Development, Bethesda, Maryland.
Insights
Environmental enrichment and low early fearfulness in rhesus monkey infants positively impact problem-solving and motor skills. Early temperament and environment interact to influence developmental outcomes.
Area of Science:
- Primatology
- Developmental Psychology
- Behavioral Neuroscience
Background:
- Early life experiences significantly shape development.
- Temperament and environment are key factors in developmental trajectories.
- Understanding these interactions is crucial for optimizing outcomes in nursery-reared animals.
Purpose of the Study:
- To investigate the combined effects of early temperamental characteristics and environmental enrichment on developmental measures in rhesus monkey infants.
- To assess how early temperament (fearfulness) and rearing environment influence later problem-solving, motor skills, and stress responses.
- To determine if environmental enrichment can mitigate potential negative impacts of early fearfulness.
Main Methods:
- Twenty-three nursery-reared rhesus monkey infants were studied.
- Early assessments (1st month) evaluated interactive, motor, and temperamental capabilities, focusing on fearfulness.
- Later assessments (8 months) measured problem-solving, motor skills, and temperamental responses under challenge.
- Infants were reared in either standard laboratory cages or enriched environments.
Main Results:
- Environmental enrichment was associated with higher scores on subsequent problem-solving and motor tests.
- Early fearfulness ratings interacted with environmental enrichment.
- Infants reared in enriched environments AND rated low on early fearfulness performed best at 8 months.
- Infants reared without enrichment AND rated high on early fearfulness performed poorest.
- Environmental enrichment partially attenuated the negative effects of high early fearfulness on problem-solving.
Conclusions:
- Early temperamental fearfulness in rhesus monkeys can predict poorer problem-solving performance under challenge.
- Environmental enrichment plays a significant role in enhancing developmental outcomes.
- The combination of enriched environments and lower early fearfulness is optimal for development.
- Environmental enrichment can buffer the adverse effects of early fearfulness, highlighting the importance of supportive rearing conditions.
Abstract:
This study investigated the combined effects of early temperamental characteristics and environmental enrichment on a variety of developmental measures in nursery-reared rhesus monkey infants. Twenty-three infants, reared in either standard laboratory cages or enriched environments, were tested during the 1st month of life for interactive, motor, and temperamental capabilities and characteristics. At 8 months of age, all subjects were assessed on a second series of tests designed to measure their problem-solving skills, motor capabilities, and temperamental responses under challenge. Results indicated that enrichment was associated with higher scores on subsequent problem-solving and motor tests. However, such effects were found to combine with early temperament ratings. Specifically, individuals performing best on the 8-month tests had not only been reared in enriched environments, but also had been rated low on fearfulness during the early assessment. In addition, individuals scoring poorest had been rated as fearful initially in addition to being reared without enrichment. Results indicated that while high ratings on early laboratory assessments of fearfulness may be predictive of poorer problem-solving performance under challenging conditions, these adverse effects may be partially attenuated by environmental enrichment.
