  We study the dynamical generation of scalar mesons in the light quark sector
($q\in\{u,d,s\}$) and calculate the masses and widths for the
$f_0(500),a_0(980)$ and $f_0(980)$. To this end we study the mixing of
conventional $q\bar{q}$ and `exotic' $q\bar{q}q\bar{q}$ states via a coupled
set of two-body Bethe-Salpeter equations based on a symmetry-preserving
truncation of the underlying Dyson-Schwinger equations. This allows us to
determine the dominant components of each state. Furthermore, we extend our
previous framework into the complex energy plane such that we can study the
analytic structure of the states in question and extract their width. At the
physical point of small quark masses, the $\sigma$ meson is predominantly a
$\pi\pi$ resonance. Consequently, its mass and width is driven by the effects
of chiral symmetry breaking. At larger quark masses, however, the conventional
$q\bar{q}$ components take over. Furthermore, we find a strong molecular
$K\bar{K}$ component for both, the strange-light $f_0(980)$ and the $a_0(980)$.
