At the preschool level, inattention from care providers has a huge impact on the child's developing language skills and future IQ scores. A six-year study by Hart and Risley (1995) that followed the outcomes of children selected from different socioeconomic backgrounds found that by age 3, the children of professional parents were adding words to their vocabularies at about twice the rate of children in welfare families. Both the quantity and the quality of phrases directed at the children by caregivers correlated directly with income levels. They found that a pattern of slow vocabulary growth helped put in place a slower cognitive pattern by the time children turned 3. In fact, IQ tests performed later in childhood showed the welfare students' scores trailing behind those of the more affluent children by up to 29 percent. Parents of low socioeconomic status are also less likely to tailor their conversations to evoke thoughtful and reasoned responses from their children.
Going hand in hand with language acquisition, reading is one of the most important factors affecting the development of a child's brain. Reading skills are not hardwired into the human brain; every subskill of reading, including (but not limited to) phonological awareness, fluency, vocabulary, phonics, and comprehension, must be explicitly taught. This teaching requires attention, focus, and motivation from the primary caregiver. Again, the time and expertise to make this happen are unfortunately in short supply among poor families. Evidence suggests that poverty adversely alters the trajectory of the developing reading brain (Noble, Wolmetz, Ochs, Farah, & McCandliss, 2006).
Even when low-income parents do everything they can for their children, their limited resources put kids at a huge disadvantage. The growing human brain desperately needs coherent, novel, challenging input, or it will scale back its growth trajectory. When a child is neglected, the brain does not grow as much (De Bellis, 2005; Grassi-Oliveira, Ashy, & Stein, 2008). Unfortunately, low-SES children overall receive less cognitive stimulation than middle-income children do. For example, they are less likely to be read to by parents: Coley (2002) found that only 36 percent of low-income parents read to their kindergarten-age children each day, compared with 62 percent of upper-income parents. In addition, low-SES children are less likely to be coached in learning skills or helped with homework, and they are half as likely as their well-off peers to be taken to museums (Bradley, Corwyn, Burchinal et al., 2001; Bradley, Corwyn, McAdoo et al., 2001) and on other culturally enriching outings. They also have fewer play areas in their homes; have less access to computers and the Internet (and use them in less sophisticated ways); own fewer books, toys, and other recreational or learning materials; spend more time watching television; and are less likely to have friends over to play (Evans, 2004). Low-income parents' financial limitations often exclude their kids from healthy after-school activities, such as music, athletics, dance, or drama (Bracey, 2006).
