The temporal relation between regression and transition periods in early infancy.

According to the literature about developmental changes, periods of instability and disorganization in the social and emotional behavior in both human and non-human primate, infancy precedes major developmental achievements or transitions (Heimann, 2003; Sparrow & Brazelton, 2006). Developmental investigators have observed a more frequent and prolonged crying, clinging and bids for physical contact with mother during these periods of instability and disorganization. Some authors, according to Horwich (1974), called these periods regression periods. Rijt-Plooij and Plooij (1992) claimed that 10 regression periods could be identified during the first 20 months of human life. In an early study, Sadurní and Rostan (2002) confirmed the presence of 8 such regression periods during the first year of life of 18 Catalan babies. Their 8 regression periods were comparable to the first 8 of the 10 regression periods found by Van de Rijt Plooij and Plooij. The aim of the present study is to see whether the regression periods that we found are temporally related to some transition. We define a transition as the occurrence of a new developmental change in a child. In the present study we have used non-analyzed data from the same 18 Catalan babies (10 boys and 8 girls) as mentioned in our earlier published study on regression periods. The age of these babies was between 3 weeks and 14 months. Using a microgenetic methodology we have found 8 transitions periods in the first year of life. We have also observed a temporal relation between the regressions periods found earlier and the transition periods reported here.