  Cooperation is a vital social behavior that plays a crucial role in human
prosperity, enabling conflict resolution and averting disastrous outcomes. With
the increasing presence of autonomous agents (AAs), human-agent interaction
becomes more frequent in modern society. We investigate the impact of
cooperative and defective AAs on human cooperation within the framework of
evolutionary game theory, particularly in one-shot social dilemma games. Our
findings reveal that cooperative AAs have a limited impact on prisoner's
dilemma, but facilitate cooperation in stag hunt games. Surprisingly, defective
AAs, rather than cooperative AAs, promote complete dominance of cooperation in
snowdrift games. Meanwhile, in scenarios with weak imitation strength,
cooperative AAs are able to maintain or even promote cooperation in all these
games. Additionally, the results obtained from structured populations also
imply that the effectiveness of AAs in promoting cooperation can be maximized
by carefully considering their design and application in a given context.
