Feeling happy and secure in our relationships is a goal many people strive for, but in times of need the emotionally insecure partners may be doing us a favor by being more alert to possible danger.

Evolution may have shaped us to consist of groups of emotionally secure and insecure individuals, researchers write in the March issue of the journal Perspectives on Psychological Science.

When faced with threats to close personal relationships, people react in different ways according to their sense of whether the world is a secure place. The same reaction styles also cause people to be more or less attuned to dangers of all kinds.

Evolution would have favored a mix of these so-called attachment styles if mixed groups were more likely to survive than groups of only secure or only insecure individuals.

"Secure people have disadvantages," experimental psychologist Tsachi Ein-Dor of the New School of Psychology in Herzliya, Israel, told LiveScience. "They react slowly and then act slowly because they need to first get organized."

This notion would explain why almost half of all people in the world have insecure attachment styles, he said, despite the fact that people prefer secure types as romantic partners.

How we view the world

People who do well in relationships have what's called a secure attachment style. They tend to view the world as a safe place, and their optimism allows them to focus on tasks without being bogged down with negative thoughts. They seek out groups and work well in them.

In contrast are those who exhibit insecure attachment styles. Some people are anxious types, always clinging to their significant other, and others are aloof, or avoidant, preferring to deal with problems on their own instead of relying on their partners.

Attachment behavior is a survival adaptation, said Ein-Dor. Because infants can't survive on their own, they have to attach themselves to their parents. If an infant cries and is soothed by its parent, it learns that it can trust other people for love and support.

Those whose parents don't have time or energy to respond may learn they have to fend for themselves.

Such traits can take on different meanings in a group setting. When in immediate danger, people shouldn't necessarily take comfort in the sense of peace and safety a group can provide.

Benefits of being insecure

To test their idea that mixed groups would benefit survival, Ein-Dor and his colleagues put students in groups of threes alone in a room with a concealed smoke machine, which was switched on to simulate a fire. Groups were quicker to notice the smoke and to react to it if they contained individuals who scored high for insecure attachment.

Groups that had a member who rated high for the anxious attachment style tended to notice the smoke faster than other groups, and those that had a member rating high on attachment avoidance tended to react first, such as by leaving the room.

"This is the first [paper] I've read that has started to sway me toward the idea that insecure attachment styles are adaptations," said Paul Eastwick, a psychologist at Texas A&M University, who was not involved in the current study. "I have always favored more of a 'side effect' explanation."