The greatest attention should be paid to it, so as to obtain a clear grasp of the Mentality under consideration.
The two hands must be carefully compared--the left showing the inherited tendencies, the right the developed or cultivated qualities.

The slightest change or deviation in the markings from the left to the right should be carefully noted down or remembered.
The direction or the termination or end of the line should, above all, be distinctly noted, for the all-important reason that this shows the direction that the Mentality is inclined to develop towards.

For example, if found with the end of the line sloping downwards in the left hand, and having become straight or lying across the palm in the right--the student is safe in concluding that the subject has not been able to follow his natural bent, but by the force of circumstances has been obliged to make himself more practical, to study business methods, and to have undertaken a training towards practicality and level-headedness in order to rise equal to the circumstances that he found himself forced to meet.
In this way the student obtains an insight into the earlier conditions of the life under examination that is invaluable, especially when there is, as will be found in many cases, no Line of Destiny visible in the early years.
[Illustration: PLATE I.
THE THREE PRINCIPAL POSITIONS FOR THE COMMENCEMENT OF THE LINE OF HEAD.] If, on the contrary, the Line of Head is found exactly in the same position on the right hand as on the left, or even very nearly so, the student can be sure that there was little or no strain in the early years, but that the subject had easy conditions which were favourable, and which allowed him to develop his natural bent of Mentality.
If, however, it is found that the left hand shows a forked ending to the Line of Head, namely, one end sloping downwards and the other end straight, or nearly so, and that the right hand shows only the straight line, then the student may decide that the subject inherited from the parents two natures, the imaginative and the practical, and that he chose to develop the latter, either in the direction of business or science.
In such a case, the student may state with confidence that the parents of the subject were decidedly opposite in their characteristics.

If the line has become straight in the right hand the subject takes more after the side that was practical.
In the case of boys or men it must be remembered that they will take more after their mother's mental peculiarities, and in the case of girls or women that they more generally take after the mental qualities of the father.
On a man's left hand that has the forked ending with the upper end straight, or nearly so, the student can state that the mother was the more practical of the parents.

If on the right hand the same mark has become clearest the man developed, followed, or cultivated the mental qualities of the mother more than those of the father.