The avoidant style typically forms where expressing needs was consistently met with rejection, irritation or indifference. The child learns a solution that is efficient in that context: turn off the signal. A need that is not expressed cannot be refused.
In an adult, the pattern looks like self-sufficiency. The person seems calm in conflict, asks for little, manages alone. Physiological measurement says otherwise: in laboratory studies, avoidant adults report detachment while skin conductance and heart rate show arousal comparable to everyone else's. The signal is switched off outward, not inward.
Typical behaviours: changing the subject when a conversation turns emotional, a sudden need for space after moments of closeness, focusing on a partner's flaws precisely as the relationship approaches commitment.
It is not coldness and not an absence of love. It is a protective strategy that was once correct and stayed switched on long after the context changed.