Refer: http://askubuntu.com/questions/186895/how-to-enable-two-finger-scrolling-on-lenovo-thinkpad-t400-w540
It can be enabled also using commands, and they can go in your .bashrc after testing
xinput --set-prop --type=int --format=32 "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Pressure" 4
xinput --set-prop --type=int --format=32 "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Width" 8
xinput --set-prop --type=int --format=8 "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Scrolling" 1 0