J.R.L. (Jakob) Gismann, MSc

Research interests
PhD thesis: The eco-evo-devo of social personalities (2025)
The term ‘animal personality’ refers to the
phenomenon that in virtually all animal species, individuals differ
systematically and consistently in their behaviours. These
differences can have important eco-evolutionary implications. In my
PhD project, I studied personality variation in three-spined
sticklebacks from an integrative developmental, ecological, and
evolutionary perspective. As controlled field experiments in
aquatic environments are difficult and behaviour under lab
conditions often lacks ecological validity, we developed a
seminatural experimental mesocosm system where large groups of
sticklebacks could be followed individually over extended periods
of time.
In a number of experiments, we investigated how social and
ecological conditions can shape behaviour over different time
scales and how personality differences, in turn, can affect
ecological processes. We showed that a brief history of isolation
(~60 years) was sufficient to induce divergence in movement
behaviour between two stickleback populations and that
individuals’ behaviour can be affected by the composition of
their social group, but to a lesser degree than often concluded
from the lab. We also investigated the consequences of personality
variation for dispersal and found that certain personality types
may facilitate movement and establishment in novel environments.
Furthermore, we found that social environmental conditions
experienced early in life may affect social associations later in
life.