The research on why faith passes down in some families and not others is unusually clear. It also surprised the people who did it. You might expect the rigor of a household's religion to predict whether the children keep it. What predicts it is warmth. Warm, close, present parents, and fathers especially, transmit faith at high rates, while strict, distant parents transmit it at low rates, however orthodox. Parents dominate. Nothing a church does with a teenager outweighs what the home does.
That's an outcome. I want to get at the machinery underneath it, why the house forms a person more than any other environment can, and at what Scripture says to the same question.
Regulation is dyadic before it is individual
One experiment has been repeated so many times it's a demonstration piece. A mother sits facing her infant, interacting normally. Then she holds her face still. There's no anger and no departure, just a face that stops responding.
The infant works. He smiles, vocalizes, reaches, and does everything he can to get the face back. When it doesn't come, he disorganizes. He looks away, arches, fusses, and within a couple of minutes is in visible distress. Nothing was done to him except that the responsiveness stopped.
At the foundation, an infant can't regulate his own emotional state. His equilibrium is maintained from outside, by a responsive other, moment to moment. Regulation is dyadic before it's individual. Self-regulation is built later, out of thousands of repetitions of being regulated.
People tend to picture a child who has emotions first and then brings them to the family, but the family is where the emotions and their management are assembled. The assembly is physical. Caregiver and infant couple their gaze, their vocal rhythms, even their heart rhythms, and early synchrony predicts a child's self-control and empathy years later. In animal studies, where the mechanism is traceable molecule by molecule, maternal care alters the offspring's stress-response system for life.
So when we say the household forms raw emotion, we mean it literally. How hard a body fires under threat, and how fast it comes down, is calibrated in early caregiving.
The working model
Above physiology sits expectation. Out of repeated interactions, a child builds what researchers call internal working models. These are expectations about whether others will respond when he needs them, and whether he's the kind of being whose needs bring people or drive them away.
A child whose signals reliably brought a response learns that reaching works. If his signals brought unpredictability, he learns to escalate, and if they brought rejection, he learns not to signal. Each is a rational adaptation to a particular household. The child then carries it out of the household and applies it to everyone else, eventually including God, the church, and the question of whether it's safe to be known.
A study in Minnesota followed children from before birth for over thirty years and found that early care predicted emotional health, peer competence, and the conduct of adult relationships decades later. The prediction was never deterministic, because early care sets only a starting model and later relationships can revise it. That is the church's opening.
The models are also transmitted. A parent's own attachment pattern, assessed before the child is born, predicts the infant's, because the pattern crosses the generation through the caregiving itself. When the research says warmth transmits faith, this is what warmth is doing. It builds the model inside which everything taught will be received. A child catechized inside a model that says authority is unpredictable has learned both things, the model more deeply than the catechism.
The family as the school of emotion
The family forms a child's emotional life through three channels. Modeling is the first. Children learn what emotions look like, which are permitted, and what one does while having them, by watching the people they live with. Practices are what the parents do with the child's emotions, whether a child's fear is noticed, named, and sat with, or dismissed and punished. Children whose parents coach rather than dismiss show better regulation and better relationships for years. Climate is the emotional weather of the household as a whole (warmth, conflict, predictability), inside which every specific interaction happens.
Even vocabulary is domestic. The amount of talk about feelings in a household predicts a child's later ability to understand emotion in others. The words for the inner life are handed across the table, or they aren't handed at all.
What modeling, practices and climate have in common is that none of them can be delivered by an hour, a class, or a professional. All three belong to a shared daily life and exist nowhere else.
The cleanest experiment ever run
Damaged households show the damage, as they should if the household forms emotion. A landmark study found that adult mental and physical health tracks the number of adverse household conditions in childhood (abuse, neglect, a violent or addicted home) in a graded, dose-dependent way. The household's emotional conditions behave like an exposure.
Another study settles the causal question as far as it can ethically be settled. In Bucharest, researchers randomly assigned institutionalized infants either to remain in institutional care or to be placed with foster families. The children shared a city and starting conditions, and assignment was by lot. The children placed in families recovered in brain activity, in attachment and in emotional development, in ways the institution-reared children didn't, and the earlier the placement, the fuller the recovery.
In the only randomized comparison of family against institutional rearing ever conducted, the family won on the formation of the emotional life. What won was a household, which is a different thing from a better institution.
The honest counterweight
There's a famous literature that seems to cut the other way. Twin and adoption studies find that adult personality traits (how extraverted, how anxious by disposition) are substantially heritable, and that the shared family environment moves them surprisingly little. The finding is true and shouldn't be argued with.
But the two literatures measure different things. Twin studies measure trait dimensions across the ordinary range of families. The developmental work measures attachment patterns, regulation strategies, working models, stress calibration and emotional vocabulary, along with religious practice, which shows substantial household transmission. Those are the reactions and the models, as distinct from temperament. They show environmental transmission, and at the extremes of environment the effects are enormous.
The exact claim, then, leaves temperament to the twin studies. The household is the primary site where a person's emotional reactions, regulation, relational expectations, and practices of faith are formed, because those channels exist only in a shared daily life.
Scripture aims exactly there
The texts converge on the same domain.
And these words, which I command thee this day, shall be in thine heart: And thou shalt teach them diligently unto thy children, and shalt talk of them when thou sittest in thine house, and when thou walkest by the way, and when thou liest down, and when thou risest up. (Deuteronomy 6:6-7)
Sitting, walking, lying down and rising are the whole daily round of a household, named hour by hour. The verse is describing a climate instead of an instructional session.
The only two direct child-rearing commands in the epistles target the same thing.
And, ye fathers, provoke not your children to wrath: but bring them up in the nurture and admonition of the Lord. (Ephesians 6:4)
Fathers, provoke not your children to anger, lest they be discouraged. (Colossians 3:21)
Both commands are about the child's emotional state, and neither mentions doctrine or behavior. They name wrath and discouragement, the two great failure modes of emotional formation, as the things a father must not produce. The apostolic parenting instruction aims at exactly the domain the research says the household governs.
The design's most famous transmission story is a household story told in the grammar of climate. The letter speaks of a faith that dwelt first in thy grandmother Lois, and thy mother Eunice (2 Timothy 1:5). It dwelt there, resided there, and was the atmosphere of a house across two generations, so that Timothy from a child knew the Scriptures (3:15). He had been taught them, but more than that he knew them, the way one knows the smells of a childhood kitchen.
The qualification for eldership makes the household the proving ground in so many words. An elder must be one that ruleth well his own house... for if a man know not how to rule his own house, how shall he take care of the church of God? (1 Timothy 3:4-5). The design treats household formation as the prerequisite for church formation, because it regards them as the same skill at two scales.
For everyone the nuclear reading would leave out, God setteth the solitary in families (Psalm 68:6). Where a church might offer the person without a household a program, the design gives him a place in one.
What this means for the church
Raw emotion and its governance are formed in the household, through channels that exist only in shared daily life, and Scripture aims its formation commands at exactly that domain and that setting.
So a church that meets as an audience once a week has located itself outside the only environment in which the deepest formation occurs. A church that takes the household form, and sets the solitary in it, has placed itself inside the machinery. Coziness is beside the point. The house is where the creature is assembled.