== Lead section and scope of article == 

 Per WP:LEAD, the introductory section should define the scope as well as provide a concise overview of the entire article.  Furthermore, per WP:BOLDTITLE, the title of the article should be displayed in bold as early as possible in the first sentence.  The scope of this article is "epigenetics and behaviour", not simply "epigenetics".  Behavior is just one of many characteristics that can be affected by epigenetics.  Hence to start out the article by defining epigenetics primarily as having affects on behavor is misleading and does not adequately define the scope of this article.  Hence I have restored the original lead sentence which clearly defines the scope of the article while at the same time, I have tried to incorporate the subsequent edits.  I also included a short description of epigenetics and how epigenetics can affect behavior by influencing the development and function of neurons.