Grooming
Groom or Grooming is an action performed by pressing the appropriate button when available.
Grooming is the first step in the process to
Give Birth to a 
baby.
You have to form a couple of a female and a male Hominid to mate and create a baby. The main way to form a couple is to bond through grooming.
Grooming forms a bond between two hominids. It is possible to form a same sex couple but it is not possible to mate and create babies using that couple.
It is important to note that your hominid can't mate with a parent or a sibling. You won't be able to form a couple with them and mating isn't possible.
Mechanics[ | ]
Select a single adult or elder hominid, approach another hominid, and press the appropriate button to analyze the other hominid. You are looking for another hominid of the opposite sex and is single. The two hominids have to be single so that they can form a couple.
If the other hominid is single, the Groom action will be available. You are required to perform the groom action by pressing the button at the correct time or the attempt fails and the other hominid brushes away your attentions.
There is an onscreen indicator of the success of BONDING and it takes several successful attempts before the overall grooming and bonding process is completed. A large onscreen display will list COUPLE FORMED when the process completes successfully.
With a couple formed, it is now possible to continue the mating process. Analyzing either of the hominids in the couple will now show that the two hominids are connected as a couple.
Notes[ | ]
Benefits of precious stones
Giving a 
precious stone to an unrelated clan member will form a couple instantly without the manual grooming and bonding process.
Once the Attachment Need (BB HB 01), Attachment Need (HB 01), and Attachment Need (HB 02) neurons are learned, changing a generation will automatically form couples and babies will be born to those couples.