Scientists who move between countries or research groups as postdocs take up to nine months longer to achieve tenure at Spanish universities than those who stay put, finds a study (L. Sanz-Menéndez et al. PLoS ONE 8, e77028; 2013). The authors surveyed about 1,260 academic scientists and engineers who had earned tenure between 1997 and 2001 at public universities in Spain. Corresponding author Luis Sanz-Menéndez, director of the National Research Council Institute of Public Goods and Policies in Madrid, says that to earn tenure in fewer than five years, the study's average, early-career researchers in Spain should remain at their PhD-granting universities. “There are disincentives for people who are highly mobile,” he says, although he notes that moves explicitly directed by a mentor had no negative effects.