Every norm you follow without thinking — how close to stand to someone in conversation, what counts as rude, when to make eye contact, what a "normal" career path looks like — had to be learned somewhere. Sociologists call this process socialisation: how a society transmits its culture, values, and expected behaviours to its members, and split it into two broad phases with quite different mechanisms and consequences.
Primary socialisation: foundational, and mostly unremembered
Primary socialisation happens in early childhood, primarily within the family, and it's where the most basic elements of culture get absorbed — language itself, fundamental norms of behaviour, a first sense of identity and belonging within a family and community. Because this happens so early, in the years before most people form lasting explicit memories, primary socialisation shapes people at a level most adults can't consciously recall learning at all — the specific formative experiences that taught a person their first language's grammar, or their earliest sense of what behaviour earns approval versus disapproval, are almost never individually remembered, even though their effects persist throughout life. Sociologists generally treat primary socialisation as laying the deepest, most foundational layer of a person's cultural formation, against which everything learned later gets built.
Secondary socialisation: ongoing, and never really finished
Secondary socialisation continues throughout life, through institutions beyond the immediate family — schools, peer groups, workplaces, religious institutions, and media — and it's where more specific, context-dependent norms and roles get learned: how to behave in a classroom, what's expected in a particular job, the norms of a specific friend group or subculture. Unlike primary socialisation, secondary socialisation is genuinely ongoing rather than confined to early childhood — a person continues absorbing new norms and expectations every time they enter a new institutional context throughout adulthood, whether starting a new job, joining a new community, or adapting to a significantly changed social environment. Sociologists studying institutions like schools have paid particular attention to secondary socialisation's less obvious content — the "hidden curriculum" of norms an institution teaches implicitly, through its structure and daily routines, separate from anything explicitly taught.
What we're still unsure about
The broad primary/secondary distinction is a standard, widely used framework in sociology, but the sharp division between the two stages is somewhat more of a useful analytical simplification than a strict, universally accurate description of how socialisation actually unfolds — the boundary between "early foundational" and "later contextual" learning isn't always as clean in practice as the two-stage model suggests, and some researchers argue certain foundational aspects of identity and values continue forming well into adolescence and beyond, rather than being fully set by the end of early childhood. How malleable core aspects of identity actually remain across the lifespan, versus how much genuinely gets locked in during that early primary phase, remains an actively studied and only partially settled question spanning both sociology and developmental psychology.
This sits inside Socialisation: Primary & Secondary, one of seven topics in Culture, one of four domains in Sociology, one of seventeen subjects the app can quiz you on.