A new study says that fake smiling on the job actually worsens a person's mood and could even cut work productivity: "The research contradicts the policies of many firms whose customer-facing staff are instructed to appear cheery at all times. They include employees of public transport firms, shops, banks, call centre workers and others who have face-to-face contact with members of the public as part of their job. Lead researcher Brent Scott, an assistant professor of management at Michigan State University in the U.S. said: 'Employers may think that simply getting their employees to smile is good for the organisation, but that's not necessarily the case."