  We derive a general formula for the early time dependence of a phase space
distribution evolving according to the kinetic Boltzmann equation. Assuming
that the early evolution of the system created in high-energy nuclear
collisions can be described by kinetic theory, we calculate the scaling
behaviors for the onset of various characteristics of the transverse dynamics.
In particular, we show that the scaling behavior of the anisotropic flow
coefficients $v_n$ at early times does not depend on the details of the
collision kernel or the system composition, while at the same time it differs
from the prediction of fluid dynamics.
