No significant correlation was observed between language, IQ and the performance in DRL. In DRL 5 s, seven children adjusted their responses and six in DRL 20 s. Age was positively correlated to performance in DRL 5 s, while the response patterns in DRL 20 s were hardly predictable. In both conditions, children aged from 4.6 years old showed a lower proportion of bursting responses, a lower rate of response, a larger proportion of reinforced responses and a higher optimisation coefficient