Reference 1

A growing body of research is finding that people who play to their strengths at work:

• Are happier
• Experience less stress
• Feel healthier and have more energy
• Feel more satisfied with their lives
• Are more confident
• Experience faster growth and development
• Are more creative and agile at work
• Feel more satisfied and experience more meaning in their work.
• Are more engaged in their work

In addition there is evidence that

• Managers who focus on people’s strengths experience improved team performance and greater success.
• Leaders who focus on the strengths of employees benefit from lower levels of staff turnover, higher levels of productivity, more satisfied customers, and greater profitability.

See https://www.psychologytoday.com/blog/functioning-flourishing/201411/ten-reasons-focus-your-strengths for an overview of the evidence and research.

In addition see Linley, P. Alex; Harrington, Susan (2010). Oxford Handbook of Positive Psychology and Work. Oxford University Press. p. 327. ISBN 978-0-19-533544-6. and http://engagingminds.co.uk/sbr/wp-content/uploads/2013/02/How-strengths-based-recruitment-transforms-organisations.pdf

Details of the Gallup research.