  PHENIX has measured elliptic and triangular flow of charged hadrons in
$p/d/^{3}$He$+$Au collisions at a center-of-mass energy of 200 GeV per nucleon
pair, and elliptic flow in $d$+Au collisions at 200, 62.4, and 39 GeV. In order
to asses the origin of collectivity in the smallest systems, these results are
compared with several theoretical models that produce azimuthal particle
correlations based on initial and/or final state effects. Hydrodynamical
models, which include the formation of a droplet of quark-gluon plasma, provide
the best simultaneous description of our observations.
