How can I get my father with dementia to participate in assisted living activities and to shower?

Not sure what would help but 3 months seems long enough if he were just needing time to adjust. Is he content or agitated? Are there any other men his age and stage that he can relate to? Was personal hygiene high on his list before? Was he a joiner before? Is it his choice about the baths or are the patients automatically taken on certain days to bathe ? Could you tell him that cousin Mary is coming to visit. Let's get cleaned up!
I hope you find a way to make him more comfortable soon if he's not now. He did give the activities a try so give him some credit. Going to happy hour and listening to music is also good. Does he wear his hearing aids then? Why must he do activities if he doesn't like them? Not everyone does. Is he sleeping well at night? He may be too over medicated to join in. Were his meds adjusted after he was admitted? I guess I'm saying if his personality is way different that may be a clue. If he was comfortable at home watching tv and napping, perhaps the new has worn off and he's found his niche with the music hour.

My dad won't wear his hearing aids. I am taking him next week for adjustment and we will try again. He is sleeping well at night. He was moved to assisted living as I could no longer take care of him as I work full time.. he was never much of a participant without encouragement. No medication changes. Right now I just am concerned about his lack of interest in anything. I will try your suggestion about bathing story. Glad I found this forum

Concerned, my mom is in a NH. She has never been a particularly sociable person.

When she was in an Independent Living facility, she would go to an activity if there was a resident she knew and like who was also going. For mom, it was ( and always has been ) about individual relationships with others, not the activities themselves that were the draw.

People are who they are, and tend to become more so as they age.

My sister in law frequently frets over mom's lack of participation. My brother and I point out to her that SHE likes to participate, but that it's never been mom's MO.

I regret the time I spent harassing my Mom about her lack of participation. She never was a real social person. I just hated thinking of her wasting away in her little room in the nursing home. But............hindsight is twenty, twenty. If I had it to do all over again I would have just enjoyed my visits with her on her terms.

When I am 92, if I live that long, I hope people let me be me. Most likely that will be sitting in my room, reading, watching t.v. and napping.