Aims & Objectives: To document the possible impact of two different levels of poverty (poor and middle-class families)on the socio-emotional development of children. Context & background literature: Traditionally, poverty has been associated to extreme hard economic difficulties, although poverty as a complex process should be studied as multi dimentional phenomenon that impacts at different levels on human functioning (Evans & English, 2002; McLeod J. & Shanahan, 1996; Msten & Reed, 2002) . In coherence, it was generated a battery of psychological instruments and direct observations to be applied to a sample of approximately 400 Mexican subjects (50% mothers and 50% offspring's) in order to document the possible impact of two different levels of poverty (poor and middle-class families) on the socio-emotional development of children. Method of inquiry or argument: It was hypothesized that some variables like mother responsivity, could buffering the negative impact of poverty conditions on socio-emotional development in children. In consequence, amongst the considered variables are: (a) environmental variables such as density and in-home noise, (b) social variables such as family turmoil and social networks support, (c) psychological variables such as loneliness and mother responsivity. Findings & Conclusions: The results are discussed from a social-ecological perspective, taking into consideration the possibility to contrast the explanations derived from a mediational model versus a structural model. Applicability to the field & the work to done next: Based on the findings from this study, could be possible to identify mother's patterns behavior of interaction that promoting resilience mechanism in their children. These patterns will be useful to reduce the pernicious poverty impact on socio-emotional development in children. As Mexico is a developing country which has the highest proportion of Indian groups, at Latin American level, at future, the next challenge is to consider indigenous samples and to identify similarities and divergences with the previous results. To promote the mental and physical health and the environmental sustainability among the most vulnerable groups in developing countries, like poor people or Indian ethnics is a social and scientific compromise that needs of innovative and multidisciplinary approaches to be efficient.