The trackpad knows that I am using my thumb??

[Heresiarch]

Hi, just bought a new 2012 MBA, my first Mac ever, and I'm absolutely loving it. The trackpad is especially amazing. However, I've just found something...strange. It seems that the trackpad doesn't work best with my thumbs. Here's an example: let's say we use the two finger scrolling function. If I'm using any combo of 2 of my 4 longer fingers, it's easy to scroll and move around. It works even if the two fingers are very far away, and angled in strange positions.

But if I'm using my thumb + any of the other longer fingers, most of the time the trackpad will ignore my thumb, unless my thumb and the other finger are very close together (it always works if they're touching each other). Pinching works fine though. A little more testing with it reveals that 3 longer fingers works great at dragging/choosing stuff, while 2 longer fingers + thumb almost end in scrolling.

Ok, I'm not complaining at all - what I'm fascinated is how can it recognize that what's touching it is the thumb or not? I mean aren't all fingers the same skin and have the same capacitance? Anyone can put some input in this? Thanks.

 

[Warhawk15]

Why do you even use your thumb when scrolling?

I think the only reason it doesn't is work because your thumb takes up more space on the trackpad than any other finger.
The only way I can use my thumb when scrolling is when its in an awkward position.

Just look at the trackpad tab under system preferences, the only time its ideal to use your thumb is for zoom, rotate, launchpad, and show desktop.

 

[Heresiarch]

I like to use my thumb + index finger in a closed pinch gesture to scroll stuff, because thus I don't need to move my right hand at all while typing. I just "rotate" my right hand for 45 degrees counterclockwise with the wrist as the center. BTW my middle finger is quite a bit longer than my index finger so it's even more awkward for me to scroll with index + middle (the middle one need to bent slightly :/)

 

[Puevlo]

Well if you look at someone's hand you can tell which digit is the thumb. It's the same with Mac computers. A lesser known feature of MBA. The thumb actually has one less joint and thus has a different type of voltage to fingers.

 

[mattopotamus]

it is always a pain in the ass for me to bring up the apps via gestures b.c the thumb is so hard to read.

 

[bit density]

Anyone can put some input in this? Thanks.

This only "works" if the thumb is at the bottom of the track pad. Imagine if this trackpad had a button at the bottom, you rested your thumb on it and scrolled with your finger and clicked with your thumb.

The buttonless glass pad works exactly the same way. And I am grateful that this detail wasn't lost on the designers. I would not love this pad NEARLY as much as I do if they didn't mimic the thumb on the button methodology