The second knuckle of the thumb reveals how the subject uses or suppresses their anger and temper.
This knuckle can have a very pronounced enlargement, or can be completely smooth without any noticeable "bump".
The larger the size of the knuckle, the more volitile the temper.
When the knuckle runs smooth without any noticeable enlargement, this reveals that the anger does a "slow burn".
Slow to build, this type of temper pattern will grow gradually over a period of years before finally exploding.
Once the anger is released, it is quite venomous and non-physical.
The subject will resort to whatever they feel is necessary to "even the score", using non-direct methods such as poison or vehicular assault to obtain their revenge.
If the knuckle is very enlarged, the opposite is indicated.
The temper is physical, direct, quick to build, quick to blow, and just as quickly the anger is released.
Due to the potential for extreme violence, these subjects have learned how to suppress their strong anger, and turn it inwards upon themselves.
The result of withholding this rage is their common feelings of depression and isolation.
If either of these conditions is shown on your hands, you need to learn how to express your negative emotions before they become a problem.
Learn how to speak up when something begins to bother you, instead of holding back in an attempt to preserve the status quo (which will be disrupted anyway).
Your long-term happiness depends upon your ability to begin expressing your anger, frustration, and rage in a more productive way.
There are many support groups and counselling services which can help you with this - find the one that is right for you.
Expression, not Suppression, is the key.