Nonlinear dynamics of x(n + 1) = lambda{4x(n)(1 - x(n))}(q) is studied in t
his paper. Different from the logistic map (q = 1), in the case of q < q(1)
= (root 33 - 3)/12 = 0.22871..., there exists subcritical bifurcation beca
use the Schwarzian derivative cannot preserve its sign at the fixed point.
Moreover, when q < q(2) = 0.17585... and lambda = 1.0, a stable period 1 or
bit appears due to stabilization of the non-zero fixed point. Intermittent
chaos due to the type 3 of intermittency is also found in this system.