Even though it seems to be subconscious, or maybe learned, users prefer to touch the center of the page, and will do so when given a choice.

In a recent test I performed, people naturally moved a list of content to the center of the screen before selecting it. When you account for content position and different devices, you find that most taps are in about the center half of the page.

Place key actions in the middle half to 2/3rds of the screen, and place options, and secondary paths along the top and bottom of the screen.

Figure 2—Whenever given the choice by scrolling to select items, people will choose the center of the screen. They will also tend to select labels, not just rows, so there is a notable left-side preference.

References