My book, "Cultural Evolution in the Digital Age" was out two weeks ago. As promised, I follow with some threads on the content of individual chapters. Here the fourth one. 1/7 amazon.co.uk/Cultural-Evolu… 
After cues related to prestige (chapter 3), we move to popularity. The popularity of everything online is long-tailed, with few big winners and many not-su-much. 2/7
This, however, (i) is true for many cultural domains (from baby names to neolithic pottery decorations) and (ii) can be produced, among other things, by unbiased social transmission. 3/7 royalsocietypublishing.org/doi/abs/10.109…
Conformity (i.e. an explicit preference for popular choices) is more elusive, and, as we discussed for prestige bias, experiments show it is modulated by many other factors, including previous knowledge, content of the traits, etc. 4/7
Another aspects of online digital media is that popularity can be quantified and made explicitly (think the number of “likes”). This has interesting consequences but, again, it does not make us following the majority cluelessly. 5/7
The chapter then move to the effects of online reviews. That’s not particularly studied from a cultural evolution perspective (but see below!) but there are a few surprising take-home messages. First, online reviews are generally truthful. 6/7
Second, the problem with reviews, contrary to the popular idea that everybody is mean on the internet, is that they are overwhelmingly positive! (Usually, the distribution is J-shaped shown below). 7/7
The goodies: a detailed discussion of the “artificial music market” experiments, proposing that, despite how the paper is often presented, the effects of popularity cues are not too troubling. science.sciencemag.org/content/311/57…
The story of “The Shed at Dulwich”, the (non existent) restaurant that become the tripadvisor top-rated in London vice.com/en_uk/article/…
The problem with online reviews of medical treatments is that they are too positive! @mdbarra studies reporting bias ncbi.nlm.nih.gov/pubmed/28190628
