I think it depends on what you mean by trust. As adults, offering and earning trust are often reciprocal processes. Both people have to accept that we all have faults weaknesses and bad days. Both people have to have boundaries, but to be willing to be flexible to an extent as they learn each other's vulnerabilities. Taking it slow, and not expecting too much all at once, as trust is a slow growing and building process.
One way we can get a handle on our own issues in this area can be to get an understanding of our own current levels of attachment security. This theory helps us understand that the experiences we have as babies, children and adults all affect us to produce our current working model of relating, which we then apply.
If my background has been difficult in areas of relating to others, therefore, my current working model I apply in relating will show low trust in others. Depending how I reacted to that, I may have developed a thick skin and so I think I m ok in this area, it's them who are untrustworthy, or a thin skin, so I think I am unworthy, everyone is better than me in all sorts of ways.
Thirdly, if things have been really tough, as they often have for people with autism who have additional confusion due to slow processing and other communication issues, I may have little faith in myself or others either.
We can work on our own self esteem, assertiveness and self image, join a class, go to therapy, read and practice self development, watch videos etc, to raise our own confidence in ourselves, while also adjusting our judgements or expectations of others. This will improve our abilities to have realistic, compassionate and tolerant views and expectations of others and of ourselves, so that our working model of how things are changes to enable us to form healthy adult attachments.
Give and take, ups and downs, good days and bad days, recriminations and forgiveness, talking things through, mutual respect for differences, tolerating aspects of others, and so on, this is the reality of secure relating.
