Fresnel Reflection
There is a Fresnel Reflection (pronounced fray-NELL) slider in the reflectivity section of the Advanced Material Editor. This setting increases the reflectivity of surfaces at glancing angles. It does not alter the reflectivity of materials at perpendicular viewing angles. Turning this setting down may offer more control when only slight reflectivity is desired.
The Fresnel slider is on the Advanced material editor. It will have more effect on objects which are less reflective, than on objects which are more reflective.
This is a teapot with ordinary reflection set to 0.23 and no Fresnel reflection. There is a light on the back wall, above the teapot, creating the reflection on the top of the teapot, and a light in front of the teapot on the right creating the reflection on the front.
This is the same scene, with reflection set down very low - 0.02 and Fresnel reflection set to 1.00. This causes the reflection at sharp angles to appear - on the top of the teapot, but not the reflection at normal angles - on the front.