Cannot capture Android http traffic

INTRODUCTION: Wireshark is set up and works completely fine on MacOSX Mavericks. There are several devices connected to the home router which can be successfully monitored. Http traffic from all devices such as Windows 7 and even iOS devices can be captured via WiFI.

PROBLEM: No http traffic can be captured from Android devices. Traffic from all devices such as Windows 7 and even iOS devices can be captured, EXCEPT TRAFFIC FROM ANDROID DEVICES. There is however a connection with Android devices because a TCP protocol has been 'intercepted', however no http traffic is shown. Problem is initially thought to be because of the several 802.11b/g/n settings, but the router, Macbook WLAN adapter as well as all devices support 802.11n.

GOAL: Capture and monitor also, and especially, Android http traffic on Macbook MacOSX Mavericks.

KEY INFORMATION: There is no physical access to other devices, meaning the option to set up certain ports or configure network settings on other devices, is not available.