Jone L. Pearce, Distinguished Professor Emerita of Organization and Management at The Paul Merage School of Business put together a leadership inventory consisting of the four best-established (and in the public domain) predictors of leadership success.
The 4 skills and scholarly reading to support them are as follows:
Gangestad, S., and Snyder, M. 1985. ’To Carve Nature at its Joints’: On the Existence of Discrete Classes in Personality, Psychological Review, 92, 317-349.
Ashford, S. J., and Tsui, A. S. 1991. Self-regulation for Managerial Effectiveness. Academy of Management Journal, 34, 251-280.
Ferris, G. R., Davidson, S. L., and Perrewé, P. L. 2005. Political Skill at Work. Mountain View, CA: Davies-Black.
Harris, J. N., et al. 2015. Power, Politics, and Influence in Organizations. International Encyclopedia of Social and Behavioral Sciences, 2nd. ed. 18, 770-775.
Law, K., Wong, C. and Song, L. 2004. The Construct and Criterion Validity of Emotional Intelligence and Its Power Utility for Management Studies, Journal of Applied Psychology, 89, 496
Roberts, R. D., and Barsade, S. 2008. Human Abilities: Emotional Intelligence. Annual Review of Psychology, 59, 507-536.
Conger, J. A., and Kanungo, R. N. 1998. Charismatic Leadership in Organizations. Thousand Oaks, CA: Sage Publications.
Den Hartog, D., et al. 1999. Culture Specific and Cross-culturally Generalizable Implicit Leadership Theories. Leadership Quarterly, 10, 219-256.