Introduction: Trust is one of the most important synthetic forces within society. Conceptually, trust is also attributable to relationships within and between social groups (history, families, friends, communities, organizations, companies, nations, etc.). It is a popular approach to frame the dynamics of inter-group and intra-group interactions in terms of trust. There is a general consensus among contemporary social scientists that social trust is important, as the small flood of recent publications on the topic shows. The interest in trust covers, unusually, in the increasingly fragmented and specialized academic world, sociology, political science, economics, psychology, history, political theory and philosophy, management and organization studies, and anthropology. Trust, it is said, contributes to economic growth and efficiency in market economics, to the provision of public goods, to social integration, co-operation and harmony, to personal life satisfaction, and to democratic stability and development, and even to good health and longevity. Trust is also at the center of a cluster of other concepts that are not less important for social science theory than for practical daily life, including life satisfaction and happiness, optimism, well-being, health, economic prosperity, education, welfare, participation, community, civil society, and democracy. And, of course, social trust is a core component of social capital, and is normally used as a key indicator of it, sometimes as the best or only single indicator. The aim of this research is a study of socio-economic determinants of trust among labor children referring to NGOs in Tehran.

Method: This study is a correlational study that was conducted with survey method. The population of the study was all 13 to 18 year old children who are referred to children support center (including Iliya institute, Shush children home, Naser Khosro children home, Moulavi all children center and science Home) in Tehran. A sample of 105 working children was selected by convenience sampling according to inclusion and exclusion criteria. The research instrument was a social trust questionnaire. The questionnaire consisted of 25 items and five dimensions including behavior-based trust, cooperative tendencies, openness, honesty, reliability. The face validity of the questionnaire was approved by 12 experts of university of social welfare and rehabilitation sciences in the fields of: social welfare, social work, social policy, sociology, psychiatry, social medicine, and psychology. Also, construct validity which was performed by principal components analysis showed that there is only one factor that explains 52. 92% of the variance and all the items loaded on this factor. To determine the reliability of the questionnaire a pilot study was conducted on 30 labor children. Then, after ensuring questions are understandable for the target group and calculating the coefficient alpha, the final questionnaire was developed and completed. Cronbach's alpha coefficient of the questionnaire was 0. 954 and Cronbach's alpha coefficients for five dimensions of the questionnaire were 0. 971, 0. 971, 0. 966, 0. 969, and 0. 967 respectively. Data were analyzed using SPSS statistical software and multiple linear regressions.

Findings: The results showed that 85 percent of the samples were girl, 73 percent had Afghan nationality, 3 percent were illiterate, 90 percent were in elementary school and only 7 percent had high school education. In addition, 66 percent of them lived with his families and other children lived with relatives, friends, and in the supportive centers. Also, the average family size was n = 6. 85 for working children. 77% of their parents lived together and another 23% were divorced or one parent had died. Furthermore, average income of children was 539,000 Tomans monthly (between 90,000 to 1,300,000 Tomans). The findings about the children's job showed that shopkeeper and peddler were the most important jobs. The results showed that social trust was at intermediate level (64. 24 +/- 10. 08) among labor children. In the aspect of social trust, the behavior-based trust mean was 13.3 (between 6 to 21), a cooperative tendency was 8.92 (between 5 to 21), openness was 12.41 (between 6 to 19), honesty was 14. 13 (between 9 to 21), and reliability was 15.48 (between 9 to 20). In addition, among the economic and social factors examined including age, sex, income, family size, place of birth, nationality, and housing situation only income and nationality significantly associated with social trust. These two factors together explained about 28.6 percent of the social trust variance. 

Discussion: Considering the fact that healthy living is a product of social interaction and trust is a key factor in the formation of interaction, it is necessary to attempt for maintain and strengthen the trust in society. Furthermore, due to the fact that working children have more social, economic and family problems than their peers and taking into account the fact that these children could potentially be involved in social problems, that also impose costs on other people, providing appropriate programs to increase their social trust can be a method of improving children's social health and, consequently, social well-being for society.