Everybody in a family has a role and a relationship with everyone else in the family. How we treat each other, how we interact with each other and what we expect from each other impacts how children growing up in a family develop. The term "family processes" refers to the functions and relationships of members in a family.
Secure attachment in infancy is a vital for the healthy development and psychological health of the growing child. Brenda Jones Harden, writing for Princeton University, points out that children whose caregivers are warm and consistent foster secure attachment. She goes on to explain that, in families with inconsistent or cold caregivers, the children sometimes develop attachment disorders that affect their ability to trust others throughout life.
In "The Handbook of Early Child Development," Michael Guralnick discusses that the quality of parent-child interactions, over time, has a direct correlation to the child's intellectual development. "Sensitive-responsiveness" refers to how the parent responds to the child. Parents who respond to their children with warmth, conversation, and logical consequences foster their children's critical thinking skills and intellectual development. In other words, the child's place as an important and respected member of the family has a positive effect on intellectual development.
Cognitive Development and Poverty
Poverty causes stress and strain in any family. Children often pick up on parents' stress -- even if parents do their best to hide it. Young children may feel isolated or lonely, while older children whose parents are struggling with poverty may feel insecure. Stress in the family affects the child's emotional development. In addition, families in poverty often cannot afford to meet all of the child's needs, including school supplies, clothing and adequate nutrition. This has deleterious effects on the child's cognitive development. Nutrition is necessary for brain growth, and, without food, sleep, and school supplies, the child is at risk for falling behind in school.
New Zealand's Ministry of Social Development published a literature review of the effects of different family processes on child development in 2005. In general, the authors found that, while children with a step-parent are often better off materially because the additional parent brings additional resources, many children in step-families exhibit more problematic behavior than those in single-parent households. Relationships and family processes in step-families are much more complex than in other families, which could contribute to the behavioral difficulties.