Background. The process of intellectual ontogenetic development and the ways for its evaluation have been studied by many prominent psychologists Piaget (1973), Wallon (1942), Zaporozhets (1986), Galperin (1998). However, there are few works which consider the zone of proximate development (Vygotsky, 1983) during evaluation of intellectual development in children.
Objective. The present study is an attempt of elaboration and application of such procedure to children who live in different social and economic conditions.
Sampling. The study took place in Mexico. 1120 school children of both sexes from different levels of living (rural, suburban, lower urban and higher urban) were selected. The age of children was from 6 to 12 years. Each socio-economic group consisted of 280 children: 20 children from each school grade (10 girls and 10 boys). The school grades comprehend the last grade of kinder garden and 6 grades of elementary school according to educational system in Mexico.
Methods. The Scheme of Evaluation of Intellectual Development was elaborated and applied to all children. The Scheme represents the evaluation of the zone of proximate development as the plan of fulfilment of the experimental task (verbal, images or actions) after presentation of orientation base of action (Galperin, 1976; Talyzina, 1984; Karpov, 1983; Talyzina, Karpov, 1987). The Scheme consists of two intellectual tasks, which are presented in different plans of intellectual development: verbal, images or actions.
Results. At first, the possibility of initial execution without helping has been verified. The results showed impossibility of execution of the initial task: 82% in rural group; 74.64% in suburban group; 64.64% in lower urban group and 71. 42% in higher urban group for the first task and 65.35% in rural group; 62.50% for suburban group; 52.85% for lower urban and 46.42% for higher urban group. The analyses of variance pointed out significant difference between the groups. However, that, after the orientation base of action has been provided, the majority of children who had failed in the initial task was able to realize it on different levels. The execution on verbal level was very high: 62.17 % in rural group; 61.27% in suburban group; 75.30% in lower urban group and 77.95% in higher urban group for the first task and 48.00% in rural group; 56.80% for suburban group; 59.58% for lower urban group and 66.14% in higher urban group for the second task. Significant difference was found only for levels of helping during presentation of orientation base of action.
Conclusions. These results show the ability of children from all groups to work in the zone of proximate development and realize the intellectual task after previous orientation. According to our study children are able to achieve verbal level which indicates the existence of broad zone of proximate development. The discussion is based on the paper of the zone of proximate development (Vygotsky, 1991) and of the orientation base of action given by adult (Galperin, 1996; Talizina, 2000) in the formation of intellectual activity in pre-scholars and scholars from different social and economic groups.