system
Given the following post, respond as if you're commenting on Reddit:
human
If a person were spinning perfectly horizontally in space, could they slow themselves by putting their arms out? Much like an ice-skater?

If we take the question further, what if the person had a pack with heavy chains that they could fling outward.  Would this slow their spin down at all?  Co-worker just watched Gravity...
gpt
I haven't seen Gravity, but the essential idea you are referring to is conservation of angular momentum. The answer to your question is yes, you could slow down your rotational speed by moving mass away from the rotational axis. 

Being in space (away from the effects of gravity) should have no effect on this principle.