example would be a third gender, a tenth planet i this solar system, a shape complementing circles

The science of psychology benefits society and enhances lives. Psychologists examine the relationships between brain function and behavior...

Psychology is at best a pseudo-science and it does not have the rigor of the physical sciences. Thus the predictions of psychological theories should be taken with a grain of salt. This is because human behavior and thinking is influenced by so many variables and no matter how careful you are conducting experiments and collecting data the R-square value can never compete with those from physical science experiments due to the large variability. Having said that the best predictor for a psychologist in terms of treating a patient successfully would depend upon how well the psychologist has learned from past patients and experiences and use that knowledge when dealing with the current patient, as well as how well the psychologist uses empathy and listening skills during patient interactions. A many decade old video in black and white shows that a patient when interviewed by three different psychologists reacted most favorably and positively with Carl Rogers (compared with two other psychologists) who emphasizes on empathy and unconditional positive regard for the patient.

Psychology even both applies and rejects the statement, depending on which branch of it you'd categorize into: Ultimately they inform each other and are growing closer together as time goes by. 

Follow,

my opinion is psychology purely related to affection and loveliness. here we need only kindness. no science behind this

It is a science.