If someone collects data and the study outcome is not preregistered, you can assume p-hacking. It would be implausible not to. And in most fields, preregistration is not common. (And even if there's preregistration, regularly people just switch their outcomes, and nobody cares.)
And to play the devil's advocate: psychology is probably doing better these days than most other fields, because it's been the posterchild example of the replication crisis.
If someone collects data and the study outcome is not preregistered, you can assume p-hacking. It would be implausible not to. And in most fields, preregistration is not common. (And even if there's preregistration, regularly people just switch their outcomes, and nobody cares.)
And to play the devil's advocate: psychology is probably doing better these days than most other fields, because it's been the posterchild example of the replication crisis.