  We examine what happens in a population when it experiences an abrupt change
in surrounding conditions. Several cases of such "abrupt transitions" for both
physical and living social systems are analyzed from which it can be seen that
all share a common pattern. First, a steep rising death rate followed by a much
slower relaxation process during which the death rate decreases as a power law
(with an exponent close to 0.7). This leads us to propose a general principle
which can be summarized as follows: "ANY abrupt change in living conditions
generates a mortality spike which acts as a kind of selection process." This we
term the Transient Shock conjecture. It provides a qualitative model which
leads to testable predictions. For example, marriage certainly brings about a
major change in environmental and social conditions and according to our
conjecture one would expect a mortality spike in the months following marriage.
At first sight this may seem an unlikely proposition but we demonstrate (by
three different methods) that even here the existence of mortality spikes is
supported by solid empirical evidence.
