In the context of portfolio management, diversification plays a crucial role in mitigating risk and enhancing returns. Consider a portfolio consisting of three asset classes: equities, fixed income, and real estate. The correlation between these asset classes is as follows: equities and fixed income have a correlation of 0.2, equities and real estate have a correlation of 0.3, and fixed income and real estate have a correlation of 0.1. Given these correlations, assess the overall risk reduction achieved through portfolio diversification.
What is the primary reason for including multiple asset classes in a portfolio?