Matthiessen (1995: 252):
(1) Certain behavioural processes that are confined to the self may occur with or without a reflexive pronoun; these include processes of grooming — behave (oneself), clean (oneself), comb (oneself), [un]dress (oneself), hide (oneself), prepare (oneself) for, shave (oneself), stretch (oneself), wash (oneself):
Blogger Comments:
To be clear, the possibility of a reflexive pronoun in such clauses rules out these verbs as serving as behavioural Processes, because, if the pronoun is interpreted as the Range of the Process, it is not a Behaviour, as it must be for behavioural clauses, and if it is interpreted as the Medium of the Process it is not a Behaver, as it must be for behavioural clauses.
Cf this impossibility for genuine behaviourals: *stare oneself, *grumble oneself, *frown oneself, *sneeze oneself, *stand oneself
Note that instances like he laughed himself sick are material clauses, as demonstrated by the inclusion of the resultative Attribute sick.