Two different questions
A personality test asks how you are in general: talkative or quiet, organised or spontaneous, calm or easily rattled. An attachment test asks something narrower: what happens inside you when someone you love goes quiet, wants more, or might leave. You can be the most outgoing person at a party and still freeze when a partner says 'we need to talk.'
That is why the two can seem to contradict each other. A confident, sociable person can be anxiously attached in romance. A warm, agreeable person can still feel uneasy depending on a partner. Neither result is wrong. They are measuring different parts of you, and the overlap between them is smaller than people expect.
What the Big Five measures
The Big Five is the trait model most personality researchers use. It scores five broad dimensions: openness to experience, conscientiousness, extraversion, agreeableness and neuroticism, which is the tendency to feel negative emotions strongly. Each is a sliding scale, and everyone has a score on all five rather than belonging to one group.
Traits are fairly stable in adulthood and become more so with age. A review of 152 longitudinal studies by Roberts and DelVecchio found that the consistency of people's trait rankings rose from about .31 in childhood to .54 in the college years and .64 at age 30, levelling off around .74 between 50 and 70. Stable, then, but never completely fixed.
What type tests do differently
Many popular personality tests sort people into types, often one of 16 four-letter types, as the MBTI does. Types are easy to remember and fun to share, and they give people a vocabulary for their differences. The trade-off is that a type turns a sliding scale into a yes-or-no, so two people just either side of a line get different letters while being almost the same.
Attachment has the same issue. The four style labels are useful shortcuts, but when Fraley and colleagues tested whether attachment differences form true categories, the data fitted continuous dimensions better. In both cases the most informative result is where you sit on each scale, not only the label printed at the end.
How attachment and personality overlap
They are related. In early research, Shaver and Brennan found that attachment styles were linked in predictable ways to the Big Five, especially to some of its narrower facets, but were not simply the same thing under a different name. In practice your traits can colour your attachment pattern without deciding it. Plenty of people are calm in general and anxious only in love.
Stability works differently too. Fraley and colleagues tracked adults weekly for a year and found the Big Five showed a similar pattern of stability to attachment, but the traits did not account for the stability of attachment. Something about how you handle closeness holds steady on its own terms, separate from your broader temperament.
Why knowing both helps
For relationship questions, attachment tends to be the sharper tool. In Shaver and Brennan's study, broad personality scales were generally weaker than attachment measures at predicting how romantic relationships went, probably because attachment is more specific to that part of life. Personality fills in the rest: how you handle work, friends, plans and stress.
Put together, they explain things neither does alone. Anxious attachment with high conscientiousness might look like planning every detail of a relationship to keep it safe. Avoidant attachment with high extraversion might look like a busy social life that never quite lets one person in. Same style, different texture, and different advice about what to change.
Getting both in one go
If you already know your MBTI letters or your Big Five scores, attachment adds the missing piece: how you behave when a relationship feels at stake. If you only know your attachment style, your traits explain why yours looks the way it does. Both also move a little over a lifetime; attachment anxiety and avoidance tend to decline with age on average.
The free test gives you both from 20 statements in about three minutes: your attachment style and a Big Five personality snapshot, with an optional full report that connects them. If personality is your main interest, there is more on the Big Five personality test.