Scientific
investigations and ethical justifications are two different things
and they both relate differently to scientific explanations. In the
former you are using the scientific method to produce an explanation,
in the latter you are using these explanations, as product of the
scientific method , to justify an ethical position.
Usually,
from a sample of a particular behaviour (you’re right in remarking
that these samples are often limited to contemporary occidental
culture, but researchers are aware of that and are expanding the
sample of culture they are investigating, eg. historical records,
isolated tribes, etc.) a scientist try to detect some correlations
and to infer from these regularities some necessary conditions or
process that explains, in part, the particular causal history of
events that led to these behaviours. Admittedly, these various
elements of scientific explanations are use to ethically justify
human behaviours, but using science to ethically justify a behaviour
is not the same thing as using science to explain a behaviour.
