What is grit? I define grit as "passionate perseverance despite failure".
Research shows that grit is associated with career success, along with high consciousness (personality trait) and particularly high IQ (general intelligence) [1].
Contrary to consciousness and IQ that are "programmed" by our genes and developed through proper parenting/schooling, grit is one of the few abilities that can be actually taught or learned, even in later stages of life [2].
So, if you are a hiring manager and you want to identify grit in your candidates, here is what you can do at every recruitment stage:
Employer branding. Share the success stories of your employees that you consider gritty. Make sure that gritty candidates could identify with your gritty colleagues. A good example will always attract good people.
Pre-screening. Look in the CV or LinkedIn for hints of projects that required a lot of time and effort and had a high risk of failure. If the candidate managed to surf through the project and feels proud about it, whether the project succeeded or failed, the person might be gritty.
Interviewing. While listening to the person's story, look for hints of perseverance and passion. People who are considered gritty do not give up easily, maintain focus, and are able to postpone pleasure, e.g. product shipment, high revenues, etc. You can also ask to provide specific examples.
Psychological assessment. If you have the resources, you can always test people using personality tests. Here is an example of a valid and reliable one: https://angeladuckworth.com/grit-scale/. However, do not trust only in the test results, see the bigger picture.
Here is a list of red flags that may indicate a lack of grit:
Tendency to switch between jobs or projects without no particular reason (however, do not jump to conclusions without hearing the candidate's story first)
Tendency to drop out of the university or college, especially during the last years of study (however, make sure that the person just did not choose an interesting job over boring studies)
Difficulty keeping attention on a single task, especially if the task is supposed to be interesting and engaging (this is more visible during hands-on technical interviews)
Lack of passion or excitement about one's job, area of interest, or field of expertise (gritty people are usually "geeks" in their own unique way and they will let you know about their nerdiness during the interview)
How grit you are? Make sure to reflect!
[1] Duckworth, A. L., Peterson, C., Matthews, M. D., & Kelly, D. R. (2007). Grit: Perseverance and passion for long-term goals. Journal of Personality and Social Psychology, 92(6), 1087–1101. https://doi.org/10.1037/0022-3514.92.6.1087
[2] Hwang, M. H., & Nam, J. K. (2021). Enhancing Grit: Possibility and Intervention Strategies. Multidisciplinary Perspectives on Grit, 77–93. https://doi.org/10.1007/978-3-030-57389-8_5