It is always a good idea to try to understand things.  Scientific approach and all that.  The idea of looking at pressure in a wing as the main factor of increased stability is not a good reference.  Let's try a simple example to illustrate this.  Take a wing that flies at 36 km/h (not unreasonable and it makes for an easy 10 m/s) horizontally and lets assume that it normally has a descent rate (i.e. vertical speed) of 1.5 m/s.  Then Phytagoras gives us (mouse-clicking on the desktop calculator) an airspeed of 10.1 m/s.  When you pull big ears, downward speed will increase to say 3.5 m/s and let's for simplicity assume that horzontal speed stays the same.  This gives (more clicking) an airspeed of 10.6 m/s.  Not much of an increase, is it?  Now air pressure goes up with velocity squared, but even that only gives about 12% increase of air pressure.  It may be a bit more, depending on the change of the angle at which the cells are placed in the airflow, but I doubt it will be much more than the aforementioned 12%. 

Now what other factors influence stability when applying big ears? I'd say two other factors are of importance:

1) Your wing span decreases, giving less leverage to the wind to toss you around.  The downside of this is that some wings tend to react a lot more abrupt to weight-shift steering with big ears.

2) Your time in the air decreases. This may sound somewhat trivial, but when you are in turbulent air, the less time you spend in it, the less chance you have to get hit by it.

As you can see, the pressure in your wing will definitely be lower, when you start flying at low speeds.  Furthermore you get near the stall speed of the wing.  So in paragliding, the general aviation rule holds:  Speed = Safety.

Cheers,

Harm Voordenhout
Hengelo (Ov) - The Netherlands