1.9.1 Classification Difficulties Due to Hybridization
and Typological Thinking
As observed above, hybridization and introgression (geneflow from one population
to another) are common inCannabis. Frequent hybridization and introgression
between groups can produce continuously intergrading variation patterns that can’t
be usefully classified. Nevertheless, some continuous variation patterns can be
usefully classified, albeit arbitrarily (or by using mathematical procedures), and this
is true forCannabis.
Indeed, regardless of how confusing nature is, there is a very strong human
tendency to divide biological variation patterns into distinctive, labelled kinds—a
kind of stereotypical thinking which simplifies reality. Such conceptualization
probably is common to animals with brains, since it classifies living things as
positive (e.g. for food) or negative (e.g. as dangerous), which is obviously desirable
for survival. In philosophical analysis,“typological thinking”is a mental set or way
of thinking about things, whereby objects are viewed as belonging to perfectly
distinctive classes or categories. Objects or concepts are viewed as necessarily
belonging either to one category (black) or another (white), but neither both (var-
iegated black and white) nor something in-between (gray). This is the way many
people think most of the time, and represents an efficient means of understanding
the universe. Stereotypical thinking is acceptable so long as one has eitherfish or
fowl, but when one is confronted with something which is neither, but manifests
attributes of both, a more sophisticated kind of conceptualization is necessary.
Many have fallen into the mental straightjacket of stereotypical thinking about
variants ofCannabisdeserving recognition. The true nature of biological classifi-
cation in general, and the classification of Cannabisin particular, cannot be
accurately understood without aflexible mindset.
However, it is very difficult for many unfamiliar with the subtleties of biological
classification to escape stereotypical thinking, because conceptualization in terms of
discrete entities is embedded in human psychology. We normally assign things to
different classes or categories, with no middle ground (philosophers refer such
thinking to the“law of the excluded middle”). Many individuals appear unable to
conceptualize things except as discrete entities, and unfortunately such a rigid
mental set precludes appreciation of biological classification at the species level—
the critical classification problem posed by Cannabis. Surprisingly perhaps,
stereotypical thinking is common among scientists and not uncommon among
professional taxonomists, although it is almost unknown in theoretically- or
experimentally-oriented classification experts. The relationship of stereotypical
thinking and biological classification ofC. sativais a complex topic, and is dealt
with in detail in Small (1979a, Chap. 1). As noted later, it is feasible to concep-
tualize a strain or cultivar ofC. sativaas simultaneously belonging to different
taxonomic groups, which is confusing for most people.
A problem associated with stereotypical thought is a rigid expectation that words
used as names necessarily are unambiguous. Thisfixity of thought is reflected in
40 E. Small