  We analyze the spectral lags of a sample of bright gamma-ray burst pulses
observed by CGRO BATSE and compare these with the results of high-resolution
spectroscopical investigations. We find that pulses with hard spectra have the
largest lags, and that there is a similar, but weaker correlation between
hardness-intensity correlation index, eta, and lag. We also find that the lags
differ considerably between pulses within a burst. Furthermore, the peak energy
mainly decreases with increasing lag. Assuming a lag-luminosity relation as
suggested by Norris et al., there will thus be a positive
luminosity--peak-energy correlation. We also find that the hardness ratio, of
the total flux in two channels, only weakly correlates with the spectral
evolution parameters. These results are consistent with those found in the
analytical and numerical analysis in Paper I. Finally, we find that for these
bursts, dominated by a single pulse, there is a correlation between the
observed energy-flux, F, and the inverse of the lag, t_lag: F propto
t_lag^{-1}. We interpret this flux-lag relation found as a consequence of the
lag-luminosity relation and that these bursts have to be relatively narrowly
distributed in z. However, they still have to, mainly, lie beyond z ~ 0.01,
since they do not coincide with the local super-cluster of galaxies. We discuss
the observed correlations within the collapsar model, in which the collimation
of the outflow varies. Both the thermal photospheric emission as well as
non-thermal, optically-thin synchrotron emission should be important.
