Hereditary family signature of facial

expression

Universality in facial

expression and perception

Expressed in isolated populations.

“Eyebrow-flash” in Himba

Universality in facial perception

Humans and Apes

Blind from birth and sighted persons

Young & old

Individual facial expression “signature”

A genetic basis of inter-individual anatomical variation in facial muscles

Individual differences are stable over time

neonates Born blind Particular facial

movements Intensities, (Duchenne

and non-Duchenne smiles)

Timing Frequencies Variability Perception

Is there a unique family facial expression “signature”?

Darwin (1872) “The inheritance of most of our expressive actions explains the fact that those born blind display them, as I hear from the Rev. R.H.Blair, equally well with those gifted with eyesight”

Participants: 24 born blind and 30 sighted individuals, belong to 21 families.

Emotional states: Think-concentrate, sadness, anger, disgust, joy and surprise were induced in an individual interview of 55 minutes.

Analyses based on 18.5 hours of video

Documenting by using index of 43 facial movements

Facial expressions of Blind from birth and their close relatives

In-Out family test-Method What is the frequency of occurrence of a facial movement

of a congenitally blind person within his family relative to the frequency of its occurrence outside of his family?

The “In family” value is based on congenitally blind subjects that show a particular facial movement and is defined as

the proportion of their family members (excluding the congenitally blind members) that show this particular facial

movement.

The “Out family” value is based on congenitally blind subjects that do not show this particular facial movement, whilst

their family members do. The “Out family” value is defined as the proportion of family members of these congenitally blind subjects that shows the particular facial movement.

Results of the In-Out family test Concentration

0%

20%

40%

60%

80%

100%

120%

0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45

Facial movements

Fre

quen

cy %

Sadness

0%

20%

40%

60%

80%

100%

120%

0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45

Facial movements

Fre

quen

cy %

In family Out family

Anger

0%

20%

40%

60%

80%

100%

120%

0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45

Facial movements

Fre

quen

cy %

Results of the In-Out family testDisgust

0%

20%

40%

60%

80%

100%

120%

0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45

Facial movements

Fre

quen

cy %

J oy

0%

20%

40%

60%

80%

100%

120%

0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45

Facial movements

Fre

quen

cy %

Surprise

0%

20%

40%

60%

80%

100%

120%

0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45

Facial movements

Fre

quen

cy %

In family Out family

Summary of the “In-Out family test”

In the entire interview and in

think-concentrate, sadness, and anger,

the frequency of occurrence of a facial

movement of a congenitally blind individual in his

family is significantly

higher than that outside his family.

Three families each including two born blind brothers

These results are based on data collected during the entire interview and show that even in families with two born blind brothers the

frequency of occurrence of a facial movement of a congenitally blind individual within his family is significantly higher than that outside

his family. N=6

0

0.2

0.4

0.6

0.8

1

1.2

0 5 10 15 20 25 30 35 40 45Facial movements

Fre

quen

cy %

The classification test

Comparing the gestalt of facial movements of born blind to those of their relatives

The number of all possible partitions is: 184756

A successful classification =the blind from birth subject was classified to the group including his

family

Results of the classification test

80% correct classification over the entire interview, 75% in anger, 69% in surprise, 66% in disgust, 60% in

joy, 59% in sadness, and 54% in think-concentrate

0%

20%

40%

60%

80%

100%

Con

cent

ratio

n

Sad

ness

Ang

er

Dis

gust

Joy

Sur

pris

e

Ent

irein

terv

iew

Emotional states

Ave

rage

cor

rect

cla

ssifi

catio

n (%

)

Conclusions The correlation between

the repertoires of born-blind subjects to those of

their sighted relatives indicates a family facial expression “signature”.

It is shown that the motor patterns underlying facial expressions, have a strong

heritable basis, and that

visual input is not required.

Thanks

Prof. Eviatar Nevo *

Prof. Gadi Katzir **

Dr. Ofer Peleg * Ms. Michal Kamara *** Prof. Hagit Hel-Or ***

Prof. Danny Keren ***

Dr. Leonid Brodsky *

The Caesarea Rothschild Foundation ***

* Institute of Evolution, University of Haifa ** The Biology Department, Oranim, University of Haifa *** The Computer Science Department, The University of Haifa