Trust is the first of the six facets of agreeableness: the default assumption that people mean well, tell the truth and can be relied on. Agreeableness is the broad domain, and a person can score high on trust and low on the other five facets, or the other way round, so the two are related but not the same.
Where the scale comes from
The ten statements are the trust facet of the IPIP-NEO, such as Believe that others have good intentions and Trust what people say, with reversed statements such as Suspect hidden motives in others and Am wary of others. You rate each on five points, the reversed ones are flipped, and the ten are added, so a score runs from 10 to 50. The IPIP key page gives coefficient alpha of .82 for the scale. No norms have been published for it on its own.
What the research finds
Evans and Revelle (2008) found that self-reported trust predicted how much people risked on a stranger in an economic game, so the answers to statements like these do show in behaviour. They also found that trust and trustworthiness are different traits: how much you expect of other people, and how reliable you are yourself, vary separately. Graziano and colleagues (2007) found that agreeableness as a whole predicts helping, most clearly when helping costs something, and Jensen-Campbell and Graziano (2001) found that agreeable adolescents had fewer and milder conflicts with others. Those are findings about the domain. The other facets are morality, altruism, cooperation, modesty and sympathy, and they do not all move together; a low domain score usually comes from two or three of them.
What it is not
It is not naivety. Trust is a starting assumption, and high scorers revise it when shown a reason to.
It is not trust in any particular person. The statements are about people in general, and the scale says nothing about a partner, a friend or a colleague.
It is not kindness. Helping and feeling for others are altruism and sympathy, and a trusting person can be ungenerous while a suspicious one gives freely.
A low score is not hostility. It is a guard setting for new people and new claims, often learned from experience, and low scorers are hard to fool.
What it means for your results
A high score means you tend to assume people mean well and take them at their word; a low score means you tend to check before believing and keep your guard up. With no norms for the scale alone, the marker shows where your answers fell in the possible range, not where you stand against other people. The 120-item Big Five test scores trust against a sample of over 400,000 people and shows the other five facets of agreeableness beside it.
The trust test takes two minutes, is scored on your device and shows your score on the strip.