You might think IQ is going up, but if you look at what subtest scores are increasing, it's really just the ability to abstract and answer hypotheticals (see Flynn, 2007). This just means it is the left brain that is being developed, and it's at the expense of the right brain. And that's just what our childcare practices are doing.
Undercare, not getting the care the body and brain expects, especially influences right brain development--the initial seat of emotional development and where knowledge built from experience is initially stored. The right brain undergoes rapid development in the first two years of life when extensive calm and interactive, symbiotic, loving care is expected. Instead because of undercare, we see emotional intelligence decreasing and IQ maintaining itself (see here for the type of care expected).
As we neglect fostering how to BE (living in the present moment with one's emotions) and DO things (action intelligence), our kids grow in the ways the culture allows--in abstracting from real life into media-derived lives. People have learned to live "second-hand" lives, lives mediated by others. Unfortunately, it mostly makes for shallow unsatisfying living and orientations that are dangerous to real life. Detachment from aliveness (i.e., emotions, connections, relationships, nature) means you can make all sorts of life-destroying decisions without any sense of real consequences or pangs of remorse.
A child trying to develop with less than ideal care (undercare) is like building a house without nails. When stressors arise, as they inevitably do, the house will be shaken and mutilated. Or maybe better said, it's more like building a house without windows, or with a backdoor that doesn't open, or a staircase with no stairs. The particular defect depends on the timing of the undercare-what systems were under development when the evolutionarily-expected support was not received? You may not notice the defect until you need that aspect of the house, like when winter comes and there is no furnace. The brain doesn't have the full complement of capabilities but it isn't apparent until the foundation is needed for the next level of development. Adolescence arrives and you discover that the groundwork for serotonin receptors was faultily developed in the first year of life from the child not being carried or breastfed, leading to clinical depression.
A child trying to develop in an abusive environment is like trying to build a house during a hurricane. Actually, the house examples may be misleading. They make you think that you actually have a functional house in the end.
Perhaps it is better to use cake baking as a metaphor for childrearing (not pregnancy-one in the oven!). Like baking a cake, there is a certain timing and sequence to childrearing. If you put the salt in after everything else, it won't be well mixed. If you forget the baking powder, it will never rise. If you have the oven temperature too low, you'll end up with a dry crusty product. If you turn the oven off in the middle, you'll have unfinished batter. If you never turn the oven on, you'll have an eventually rotting mess, the ingredients gelling in some unimagined fashion. Child development is similar. If you don't pay attention to the ancestral sequence and timing of care, you will end up with pockets of undercooked, unfinished or misdesigned brain and body systems.
What concretely am I talking about?
Experience from the beginning of life can influence developmental outcomes, including social and moral outcomes. For example, in the first days of prenatal life the developing blastocyst's germ wall may be stressed in such a way that shows identifiable methylation later in disparate parts of the body (blood, brain's temporal lobe) that deletes an oxytocin receptor linked to autism (Gregory et al., 2009). What stressors might do this? Environmental effects on fetal and child development include maternal diet during gestation (with different effects depending on timing), infant and child diet, xenobiotic chemicals (e.g., bi-sphenol-A plastic), and radiation (for a review, see Dolinoy, Weidman & Jirtle, 2007). These can directly influence methylation and chromatin remodeling factors resulting in an alteration in the fetal epigenome and subsequent gene expression. This means that women who are wanting or in the condition to be able to get pregnant should be eating well, avoiding radiation, plastics and other chemicals.
Similar effects on child outcomes are found postnatally from what caregivers do or do not do.
Let's just talk about one example. 0-6 months is the preattachment phase when the caregivers' responsivity (noticing signals early and meeting the baby's needs quickly so that the baby does NOT become distressed) lays the groundwork for secure attachment later. Secure attachment, in part, represents good neurobiological development and leads to all sorts of positive cognitive, social, emotional and moral outcomes.
For example, Feldman found that responsivity at 3 months was linked to attachment later. Our work, which starts at 4 months, concurs. Mother-child responsive relationship at 4 months predicts predicts the child's self regulation, cooperation and social engagement by 18 months and older. Responsivity also predicts less aggression, depression but more competence and intelligence by age 2 and beyond.
The early months of caregiver-baby relationship is key, setting the pattern for the rest of the life (although, yes, there are other sensitive periods for different aspects, but perhaps none so key as the early mutual co-regulatory relationship).
So if you want your child to be fully alive, perceptive, social and smart, follow our ancestral practices: nurse, hold, respond, let play, and share care.
*I focused on early care here, but undercare afflicts all age groups, which I will write about in another blog. However, undercare may have its greatest effects in early life when the body and brain are being constructed.