Researchers from the University of Oxford, in the UK, have found that infants that take more daytime naps tend to develop a larger vocabulary at an earlier age than their peers by examining sleeping patterns of 246 babies between the ages of 7 months and 3 years for 10 days. Parents also completed a language analysis at the start of the study and three and six months later to determine how many words each child understood from a list 416 words typically learned in infancy. Infants that napped more frequently during the day performed better on both understanding and expressing vocabulary than the others.