Trust
A settled expectation that another person or system will not cause harm, allowing reliance without constant vigilance.
How it shows up
Trust shows up when people stop checking: handing over keys, sharing a secret, relying on a colleague's figures, assuming a bridge will hold. It lowers vigilance and frees attention for other things. It is often built slowly through reliability and can be lost quickly. Trust is less a momentary feeling than a settled expectation, which is why it can be present without being noticed until it is broken.
How it differs from Attachment
Attachment is a bond to particular people; trust is an expectation of not being harmed, which can extend to strangers, institutions, or a bridge.
Notice
Notice where you no longer feel the need to check, and what earned that.
Where it is felt
Felt most in the chest, stomach and face.
Based on Nummenmaa et al. (2014), bodily maps of emotions, and related research. The map shows where people report bodily sensation, on average; individual experience varies.