How the 2 sexes generally count the giving and receiving of love differently. Gray believes that Men give and receive points (A form of score given for every good impression made) in larger blocks. For example, men can count an expensive present as 20 points or feels that the unattached lady giving a chance to go out with her on Valentine Day as 10 points and so on.
Whereas Ladies (in Gray’s opinion) tend to give in small amount of 1 point for every good impression made. They give 1 point for every item like present (regardless of price), flowers, candles, music, privacy, location etc.
In my personal opinion of this is a yes and a ‘not really’ to the theory. Yes in the sense that there are many people falling under these category. ‘Not really’ in the sense because there are things that you can do to impress the girls to earn bulks of points (by going extra miles which I will highlight later in the post. This is also for the Ladies to judge better which guy around you that is really making effort in their courtship). There are also arguments that Sensitive New Ages Guys (SNAC) who judges the points like the females.
The 2nd difference highlighted by Gray is the difference how Men and Women react under stress. The theory by him of the ‘Cave (Men) and the Wave (Women).’ I found a simple yet detailed explanation at wikipedia for easy reference rather than typing out what the books says:
http://en.wikipedia.org/wiki/Men_Are_from_Mars,_Women_Are_from_Venus
Gray strongly believes that many men tend to withdraw until they find a solution to their problem. He refers to this as "retreating into their cave." In some cases they may literally retreat, for example, to the garage or spend time with friends. The point of retreating is to take time to determine a solution. What is known is that men in their caves are not necessarily focused on the problem at hand; many times this is a "time-out" of sorts to allow them to distance themselves from the problems so their brains can focus on something else. This allows them to revisit the problem later with a fresh perspective.
This has historically been hard for women to understand because when they are stressed their natural reaction is to talk about issues in order to find a solution. This leads to a natural dynamic of the man retreating as the woman tries to grow closer. This becomes a major source of conflict between any man and woman.
The wave is a natural cycle for women that are centered on their abilities to give to other people. When they feel full of love and energy to give to others their wave is in a stable place. As they give to others (and don't receive the same amount of love and attention given to them in return) their wave begins to grow until it eventually crashes. This is a time when a woman feels she has nothing else to give to those in her life and she needs the love of those around her (including self love) to help come out of this dark place. Once she is rejuvenated (by getting the support she needs) she is able to pop out of this dark place and once again has love and energy to give.
As one reviewer put it:
When men go into their cave, they are actually going through a phase of their relationship with a woman, when they want to be left alone. Any woman who has wondered why a boyfriend is not emailing/calling/messaging/meeting her will know what it feels like to be shut out of the cave. Women and 'the wave' is a concept [which] means that women go through periodic phases when they are unable to keep up their spirits without help and assistance from understanding men. At such times, 'the wave' crashes, and it needs to be given love and reassurance to rise up again with its usual confidence.