Science - USA (2022-04-29)

Morrillet al.,Science 376 , eabk0639 (2022) 29 April 2022 8 of 15

not toy−

directed

not toy−not toy− independent less

sociable

toy−

directed

toy−toy− biddable high

engage

aloof

entropy explained by phenotypes in mutts

0.0 0.2 0.4

coat furnishings

0.0 0.1 0.2

ear shape

0.0 0.1 0.2 0.3

leg length

staffordshire bull terrier

rhodesian ridgeback

poodle

pembroke welsh corgi

irish wolfhound

great dane

golden retriever

german shepherd dog

dachshund

chow chow

chihuahua

boxer

australian shepherd

australian cattle dog

american pit bull terrier

0.0 0.1 0.2

coat length

significant non-significant

ch

ow

austral

ian

(^) sh
ep
he
rd
7%
24%
11%
9%
49%
cocker
border colliespaniel
shi
h tzu ja
ck
ru
ss
el
l
yorks
hir
e (^) t
er
rie
37% r
25%
22%
16%
te
rri
er
go
ld
en
poodle
lab
ra
do
r
re
tri
ve
re
43%
16%
10%
31%
re
tri
ev
er
br
ee
ds
<^5
%
Maxine Jack #1 Bella
Guessed
(top two)
Genetic
ancestry
irish wolfhound (67%) chihuahua (91%) border collie (76%)
airedale terrier (25%) boston terrier (33%) corgi (70%)
Jack #2 Rosie Reilly Rudy Clarence Esme
% guessed 1% 16% 17% 27% 39% 60%
% detected 24% 30% 25% 28% 25% 26%
American
pit bull
terrier
2+ correct breed guesses
1+ correct breed guesses
fraction of participants
ratio of observed vs expected
0% 25% 50% 75% 100%
Bella
Jack1
Maxine
0.5
1
10
Bella
Jack1
Maxine
0.1
1
10
100
herding
N=9
49 other
breeds
#3 Toy-direc.
motor patterns
#4
Biddability
#7 Environ.
engagement
#8 Proximity
seeking
toy
N=12
46 other
breeds
#6 Dog
sociability
mean PPS
not signif. p<0.05 padj(BH)<0.05)
−2 0 2 −4 −2 0 2 4 −2 0 2 −2 02 −2 0 2
−4
0
4
−4
0
4
−4
0
4
toy (N=12) working (N=8)
hound (N=7)
terrier (N=6)
herding (N=9)
sporting (N=7)
t-test estimate (vs other breeds)
1357246813572468
factor
F
E
AB
C D
Fig. 5. Breed stereotypes can be assessed in mutts, where environmental
effects (e.g., owner perception) are mitigated by the difficulty of accu-
rately discerning the breed.(A) Breeds grouped by purported historic working
roles are more differentiated (measured by mean PPS) on some factors than
other breeds (58 breeds total), measured as atstatistic using StudentÕsttest.
Error bars represent 95% confidence intervals. (B) Toy and herding breeds
illustrate groups with shifts in opposite directions (full results in fig. S18).
Points are PPS for breed, vertical lines are mean PPS for group, boxes enclose
the 25 to 75% quartiles, and horizontal lines extend from 1.5 times the
interquartile range (IQR) below the 25% quartile to 1.5 times the IQR above
the 75% quartile. Arrows indicate the direction of change in means, and words
show the favored behavioral propensity. Herding breeds are Australian cattle
dog, Australian shepherd, Belgian malinois, border collie, Catahoula leopard dog,
collie, German shepherd dog, Pembroke Welsh corgi, and Shetland sheepdog.
Toy breeds are bichon frise, Cavalier King Charles spaniel, Chihuahua, Havanese,
Maltese, miniature pinscher, papillon, Pomeranian, pug, shih tzu, toy poodle,
and Yorkshire terrier. (C) For each dog in the MuttMix survey, the ratio of
observed:expected correct guesses for (i) one or more or (ii) two or more of the
highest-content breed ancestries (blue indicates a ratio >1; open circles are
not significant). (D) For six dogs that have a similar amount of genetic ancestry
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