You can give them emotional signals, but I feel like it's cruel to do so and would recommend against it.

do humans? or is it only because we're the ones doing the research and so we say we do?

i think most people are automatons and can be programmed.

it is the most moral thing to program people to operate in ways that causes least harm to everyone else around them that has to live with them.

people like certain foods, outrage, and gambling/fomo.

Nope.

They can pretend to, of course, and use the language of grief, but if you can't feel the cold bottomless pit that has bored through your gut then you aren't really grieving.

Insofar as grieving is an inherently, fundamentally a very particular chemical process, the answer is a resounding “no”.