  Young multiple systems accrete most of their final mass in the first few Myr
of their lifetime, during the protostellar and protoplanetary phases. Previous
studies showed that in binary systems the majority of the accreted mass falls
onto the lighter star, thus evolving to mass equalisation. However, young
stellar systems often comprise more than two stars, which are expected to be in
hierarchical configurations. Despite its astrophysical relevance, differential
accretion in hierarchical systems remains to be understood. In this work, we
investigate whether the accretion trends expected in binaries are valid for
higher order multiples. We performed a set of 3D Smoothed Particle
Hydrodynamics simulations of binaries and of hierarchical triples (HTs)
embedded in an accretion disc, with the code Phantom. We identify for the first
time accretion trends in HTs and their deviations compared to binaries. These
deviations, due to the interaction of the small binary with the infalling
material from the circum-triple disc, can be described with a semi-analytical
prescription. Generally, the smaller binary of a HT accretes more mass than a
single star of the same mass as the smaller binary. We found that in a HT, if
the small binary is heavier than the third body, the standard differential
accretion scenario (whereby the secondary accretes more of the mass) is
hampered. Reciprocally, if the small binary is lighter than the third body, the
standard differential accretion scenario is enhanced. The peculiar differential
accretion mechanism we find in HTs is expected to affect their mass ratio
distribution.
