Developmental changes in open‐field behavior in the kitten

Seventy‐eight kittens from 3 to 7 weeks of age were studied in an open‐field arena. Three major age‐dependent changes were noted: (1) the number of floor squares entered was markedly higher for 5‐ and 6‐week‐olds than for younger animals, and slightly lower for 7‐week‐olds than for 5‐ and 6‐week‐olds; (2) the tendency to backtrack from 1 square to a just‐vacated square decreased with age, the largest change occurring between 4 and 5 weeks of age; (3) the within‐session decrement in locomotion was largest for 3‐week‐old kittens but was smallest for 4‐week‐olds and increased monotonically with age thereafter. The results suggest a possible role of hippocampal maturation.