More U.S. adults use LinkedIn and Pinterest than Twitter, but that website attracts a greater proportion of blacks and young adults than do its social media peers, a Pew Research Center study released on Monday showed. The figure was 22 percent for LinkedIn and 18 percent for Twitter, holding roughly steady from a year ago. About 29 percent of the blacks surveyed by Pew made use of Twitter, well above 16 percent for whites and Hispanics, the study showed. (http://r.reuters.com/fyc75v) Twitter ranks higher than Pinterest in terms of engagement, however: 46 percent of users surveyed go onto the online messaging service daily, versus 23 percent for Pinterest and just 13 percent for LinkedIn.