A 2015 study involving nearly 4,700 adults examined two key attachment traits; anxiety about rejection and discomfort with closeness and found both were better explained as a spectrum, suggesting people can vary gradually rather than fit fixed relationship categories

Think about the way people behave in relationships. One person may worry constantly about being abandoned, while another may find it difficult to open up or depend on someone. It is tempting to put each person into a simple box: secure, anxious or avoidant.

But human relationships may not work that neatly. A 2015 US study published in the Journal of Personality and Social Psychology examined attachment patterns in nearly 4,700 adults and found that individual differences in adult attachment were better explained by continuous dimensions than by distinct categories. The researchers found this pattern both in people's general attachment orientations and in specific relationships, including those with parents, romantic partners and friends.

Study examined attachment across different relationships

Researchers R. Chris Fraley and colleagues from the University of Illinois at Urbana-Champaign wanted to revisit a long-running question in attachment research: are people genuinely divided into different attachment types, or do attachment-related traits exist along a spectrum?

The study used two samples. The first included 2,399 usable cases and was used for exploratory analysis. The second included 2,300 people and served as a confirmatory sample, with its sampling and analysis plans preregistered before data collection. Participants were adults between 18 and 65 years old.

The researchers assessed attachment using the Experiences in Close Relationships–Relationships Structures Questionnaire. It measured two key dimensions: attachment-related anxiety and attachment-related avoidance. Participants answered questions about their relationships with their mother, father, romantic partner and nonromantic best friend, as well as how they generally felt in close relationships.

What the researchers found

The researchers used three different methods to see whether attachment styles are best understood as fixed categories or as a range. They found that avoidant attachment was better explained as a range rather than separate types. The same was true for attachment-related anxiety.

Simply, people do not necessarily fall into a few fixed attachment categories. Instead, they can experience different levels of anxiety or avoidance.

The researchers found a similar pattern when they looked at people's relationships with their mothers, fathers, romantic partners and best friends. Most of the results supported the idea that attachment exists on a continuum, although some findings about best friends were less clear. Overall, the study did not find strong evidence that adult attachment should be divided into fixed categories.

Why this matters for relationships

The findings suggest that saying someone is simply an “anxious” or “avoidant” person may leave out important information about how that person actually relates to others.

The researchers concluded that adult attachment is best understood and measured dimensionally, regardless of whether researchers are looking at general attachment or a particular relationship. In other words, people can differ in the degree of attachment-related anxiety and avoidance they experience rather than belonging to a small number of completely separate psychological types.

That distinction matters because relationships can be complicated. A person may feel more secure in one relationship and more anxious in another. The study itself examined attachment across parents, romantic partners and friends, reflecting the idea that people's experiences with different people can vary.

The researchers also warned that forcing continuous differences into categories can discard information. They noted that when a continuous variable is divided into categories, a substantial amount of the underlying variation can be lost. That can make it harder to detect gradual changes in attachment over time.