Most of the blog provides blog roll which gives options for users to browse various blogs on different topics. Therefore every action has an equal and opposite reaction, these blog rolls also reduce your blog reputation in Google.

Matt cutts explains in Google Webmaster Help video about whether blog roll will affect blogs reputation in Google.

He explains that Blog roll will not affect blogs reputation until if you sell links for non related content website. If your blog links to your family related blogs there may be some affects in reputation.

Matt cutts clearly explains that if you are linking to non related content(Spams), which will affect your blog reputation.

Cross post from ToTheTech.Net Webmaster blog