In "The Trait That 'Super Friends' Have in Common" (2022-08-25, The Atlantic) Marisa G Franco writes of the importance of a "secure attachment" style:

According to attachment theory, there are three major attachment styles: secure, anxious, and avoidant. (A fourth–disorganized attachment–is a mix of anxious and avoidant, but it's under-researched in adults.) Secure people assume that they are worthy of love, and that others can be trusted to give it to them. People who are anxiously attached assume that others will abandon them–so they cling, or try too hard to accommodate others, or plunge into intimacy too rapidly. Avoidantly attached people are similarly afraid of abandonment; instead of clinging, though, they keep others at a distance. Attachment is a spectrum, and it can change over time; it's common, for instance, to exhibit more insecure attachment when stressed. But we each have a primary attachment style we demonstrate most often.

Franco discusses optimism as a character trait, and its correlation with feeling secure:

The psychologist Fred H. Goldner coined the term pronoia to describe the optimistic counterpart to paranoia. People with pronoia possess the delusion that, despite any evidence to the contrary, others want the best for them. But presuming goodwill isn't always uncalled for. Unless there's contradictory evidence, secure people tend to assume that others are trustworthy.

It's tempting to think that secure people are setting themselves up for disappointment. But assuming the best sets people up to receive the best. ...

And when untrustworthy people weasel through the cracks and cause harm, secure people are less affected than the insecure. Research shows that security is a strong predictor of resilience and stress regulation. ...

Accompanied by this resilience and good faith, secure people are freed up to take risks in relationships. They're more likely to initiate new friendships, as well as productively address conflict and share intimate things about themselves. ...

and

... the more positively we feel about ourselves, the more likely we are to assume that others like us. How people thought their romantic partner viewed them, the study found, was less a reflection of their partner's perspective and more a reflection of how they viewed themselves. In platonic relationships, too, how we think others view us isn't necessarily fact.

When secure people assume that others like them, this is a self-fulfilling prophecy termed "the acceptance prophecy." ... "if people expect acceptance, they will behave warmly, which in turn will lead other people to accept them; if they expect rejection, they will behave coldly, which will lead to less acceptance." ...

... the power of positive thinking!

_{(cf Optimist Creed (1999-04-16), How to Win Friends and Influence People (2008-05-17), Tough-Minded Optimists (2009-12-22), How to Be an Optimist (2011-08-24), Happiness Buffer (2013-12-22), Power of Optimism (2016-02-23), Mantra - Be on Good Form (2016-05-10), Positive Thinking Techniques (2017-09-21), Ten Resolutions by Clyde Kilby (2017-10-16), See the Good in Others (2018-01-02), Five Great Joys in Life (2019-09-24), Mister Pollyanna (2020-01-28), Worry, Stress, Anxiety (2020-03-04), Be More Optimistic (2020-07-02), Anti-Paranoia (2020-09-28), It's a Big Beautiful World (2021-05-03), ...) - ^z - 2022-09-08}