“…There is ample evidence that set-ups, where robots can share knowledge, outperform otherwise equivalent set-ups where robots learn in isolation.When robots share knowledge, they achieve better performance and/or the learning curve is steeper (Usui and Arita, 2003 ; Curran and ORiordan, 2007 ; Perez et al, 2008 ; Pugh and Martinoli, 2009 ; Garca-Sanchez et al, 2012 ; Miikkulainen et al, 2012 ; Tansey et al, 2012 ; Heinerman et al, 2015a , b ; Jolley et al, 2016 ). A higher overall performance can be observed when there is a quality or diversity assessment before the knowledge is sent or incorporated (Huijsman et al, 2011 ; Garca-Sanchez et al, 2012 ; Heinerman et al, 2015b ). Evidence by Huijsman et al ( 2011 ) and Silva et al ( 2015 ) show that robot-to-robot learning can linearly decrease learning time, e.g., the fitness measure that four robots can reach in 2 h can be reached by eight robots in 1 h when they learn socially.…”