That is interesting - one of the postulated prerequisites for sociality in insects is haplo-diploidy, where one gender is haploid and the other is diploid, like it happens in bees and ants.<p>This leads to the curious outcome where sisters are closer related to their sisters than to their daughters: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Haplodiploidy#Relatedness_ratios_in_haplodiploidy" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Haplodiploidy#Relatedness_rati...</a><p>I assume these spiders are all diploid?<p>Wikipedia says that part of the social behaviors in these spiders is that they don&#x27;t discriminate towards foreign offspring. I&#x27;m reminded of Argentine super-colonies, which are ant species which form enormous colonies stretching several hundred kilometers but which may or may not be genetically distinct - one hypothesis as to why they cooperate and not fight is this:<p>&gt;the reason ants in the Mediterranean don&#x27;t fight is that, although they are genetically diverse, they have lost the diversity in the genes that are involved in recognition and thus don&#x27;t recognize each other as different.<p>Source, 2004: <a href="http:&#x2F;&#x2F;news.stanford.edu&#x2F;news&#x2F;2004&#x2F;april7&#x2F;antstudies-47.html" rel="nofollow">http:&#x2F;&#x2F;news.stanford.edu&#x2F;news&#x2F;2004&#x2F;april7&#x2F;antstudies-47.html</a><p>Wonder whether these spiders have the same thing!