LONDON, England -- Workers distracted by phone calls, e-mails and text messages suffer a greater loss of IQ than a person smoking marijuana, a British study shows. The constant interruptions reduce productivity and leave people feeling tired and lethargic, according to a survey carried out by TNS Research and commissioned by Hewlett Packard. The survey of 1,100 Britons showed: Almost two out three people check their electronic messages out of office hours and when on holiday Half of all workers respond to an e-mail within 60 minutes of receiving one One in five will break off from a business or...