［論文］

日本インテリア学会論文報告集

33号，2023年３月

恋愛感情の有無による異性との対人距離Interpersonal Distance to the Opposite Sex due to Romantic Feelings
小林茂雄＊
Kobayashi Shigeo

要旨
男女の対人距離，特に顔見知り程度の間柄で，恋人関係
ではないが恋愛意識を持つと心の中で想定した男女の距離に着目した。室内で二人だけで会話する状況で，片方が相手との最短距離に立位で近づくように教示する実験を行った。その結果，好みのタイプの異性との距離は，男性は暗くて横並びの場合に，女性は暗くて正面方向の場合に最も近くなった。また男性も女性も，暗くて横並びの時に最も話しやすいと評価した。既に恋愛関係にあるカップルは横並びで接近するという傾向があるということは既往研究で示されているが，恋愛初期でもその状態が好まれることが確認できた。

SummaryThis research focused on the physical distance between maleand female individuals assumed to have romantic feelings but are
not yet considered as couples. While talking with just two people,
one subject was asked to adjust the position to the shortest
distance with the partner in a standing position. As a result of theexperiment, it was found that the distance to the favorite opposite
sex was the closest when men were side by side with dark lighting
and women were facing each other with dark lighting. Both men
and women also evaluated that they were the easiest to talk when
it was dark and side by side. Previous studies have shown that
couples approach side by side, and this tendency was confirmed
even in the early stages of romance.

キーワード：パーソナルスペース，恋愛感情，対面，横並び，空間の明るさ

1. Introduction
This research focuses on the physical distance between maleand female individuals with mutual romantic intentions but
are not yet considered as couples. Men and women who are inromantic relationships started out as strangers and eventuallyprogressed to being acquaintances. If one person has an interest
in another individual of the opposite sex or if both favor eachother, this usually leads to a relationship of love. The physicaldistance between romantic partners changes appropriately
depending on the stage of the relationship. As the relationshipdeepens, they become more comfortable being physically near
one another, and their close proximity makes it easier for amore intimate conversation and encourages body contact.
Previous research conducted on physical distance in relation
to the opposite sex is broadly classified into two based on
study subjects: The first type targets couples who are alreadyin romantic relationships while the second type focuses oncomplete strangers. In the former, couples have a tendency
to be within a shorter distance from their partners comparedwhen they are with friends of the same sex１–５）. On the other
hand, in the case of the latter, strangers tend to be distantand uncomfortable with the opposite sex than the same sex,
especially when an unfamiliar man approaches a woman５–７）.
＊東京都市大学建築都市デザイン学部建築学科

Keywords: personal space, romantic feeling, face to face, side by side,brightness

The purpose of this research is to examine the extent a personwith romantic interests will approach and talk to an acquaintancefrom the opposite sex. Generally, comfortable distance is observed
between partners with favorable interpersonal feelings８–10）.
However, there are a few studies that included romantic intention
with mutual feeling and almost no international studies regarding
the observation of the interpersonal distance during the earlyromance period. As a comparison of interpersonal settings, casesof same sex and opposite sex with no romantic interest are also
covered. Furthermore, lighting conditions are also taken into
consideration as a factor that seems to influence communication,
mood and distance to others. In our previous studies12, 13）, a
heterosexual couple sitting at a cafe or resting place was getting
more eye contact and approaching posture in dark places whentalking. On the other hand, personal space was affected bylighting11–14）as many results indicate that a wider distance fromothers is observed when the place is dark.
In this research, the situation to stand up and talk is set, taking
into consideration that the distance is freely adjustable with an
acquaintance partner. The orientation of the body when standing
and talking can be classified as facing each other, diagonally
opposite or side by side (shoulder to shoulder). Most of theresearch deals with distances when facing each other or when
1The favorite subject was acquaintance with opposite sex withromantic feelings and the not favorite subject was acquaintancewith opposite sex without romantic feelings. In conversations
between participants of the same sex, they displayed neutral
relationships without registering emotions such as favorite or notfavorite. Although the conversations were set up between actualclassmates (both same sex and opposite sex), the settings offavorite and not favorite were assumed by them in their minds.
After about five minutes into the conversation, it was observedthat only one side of the subject (who is the evaluator) adjusted
the position. The experiment did not intend to investigate themost comfortable interpersonal distance, but to ascertain theminimum distance that could be maintained without being
awkward. That is because proximity could be considered as afactor for making two individuals more intimate.
Table 1 shows the experimental conditions, and Figure 1
presents the situation at the time of the experiment. In theentrance hall of the university building, the experiment was
carried out under four conditions combining two conditions
where the floor illuminance was set to 300 lux and 10 lux andthe subjects stood face to face and side by side. The minimum

approaching from the side to the front. In this experiment, twoorientations are set: face to face and side by side. People are easy
to talk to in a side-by-side position as if they stand beside thewalls or along the aisles and look outside the window or towards
the center of the room４, 13, 15）. The couples tend to relax for a longtime when standing side by side, making it is easy for intimate
communication16, 17）. Studies that examined interpersonal distancesat the same time by simultaneously changing the direction of thebody, the presence or absence of romantic consciousness and thelighting condition during conversation were not conducted.

2. Experimental method
The experiment involved a conversation between twoclassmates who were familiar with each other, but were not yet
friends. The total number of subjects was 51, including 25 maleand 26 female Japanese college students in the age group 20-22
years. It was decided to conduct the experiment in a university
building in Tokyo. During the conversations, the participants
were asked to adjust their position so as to indicate that they do
not want to approach any closer. The partners of opposite sex
were asked to discuss one favorite and one unpleasant subject.

Table 1 Experimental condition
Place and time

Entrance hall of college building from 16:00 to 20:00
Bright situation: average floor illuminance 300 (lx)Lighting

Dark situation: average floor illuminance 10 (lx)Orientation withconversation partner

Face to face
Side by side
Favorite opposite sex acquaintance with romantic feelings

Supposedconversation partner

Unfavorite opposite sex acquaintance without romantic feelings
Acquaintance of same sex without likes and dislikes
The actual conversation partner is a classmate who knows eachother's face, but is neither a friend nor a lover.

Subjects

25 males and 26 females aged 20 to 22
26 opposite-sex pairs, 13 male pairs and 13 female pairs

Procedure

1. Move to the shortest distance not to be awkward whentalking to the other person.
2. Set interpersonal distance with total of 4 conditions of body
direction and lighting.
3. In each interpersonal setting answer one condition thatwas most easy to talk.
4. Describe the reason for the most easy-to-talk condition.

Subjects
25 males and 26 females aged 20 to 22
Procedure 1. Move to the shortest distance not to
be awkward when talking to the otherperson.
2. Set interpersonal distance with totalof 4 conditions of body direction andlighting.
3. In each interpersonal setting answer
one condition that was most easy totalk.
4. Describe the reason for the mosteasy-to-talk condition.

Table 2 T he result of interpersonal distance (cm)Horizontal distance between the tops ofthe heads in standing position
Male
Face
to facehorizontal distance between the heads
Favorite
opposite sex

about 60cm from
the wall Evaluator

Average

Conversation partner

Face to face

Unfavorite
opposite sex
Same sex

Side by side

Favorite
opposite sex
Standard
deviation

Unfavorite
opposite sex
Same sex
Favorite
opposite sex

MedianUnfavorite
opposite sex
Same sex

Fig. 1 Experimental situation2

BrightDark
BrightDark
BrightDark
BrightDark
BrightDark
BrightDark
BrightDark
BrightDark
BrightDark

FemaleSideby sideFace
to face

85
76
77
73
121
105
107
100
▲▲ 88 ▲▲ 7580 ▲▲ 73
22
20
18
18
36
28
26
21
34
22
22
23
80
78
77
68
120
103
110
98
84
73
78
70

T-test by gender of evaluator▲▲ ▲: Male distance is longer than female,

79
69
115
109
62
57
14
15
22
28
12
13
81
70
114
105
64
59

Side
by side
79
73
116
▽ 117
56
54
15
13
24
31
14
14
78
73
109
108
57
56

All subjects
Face
to face▲▲ ▽▽: p <0.01,

80
70
115
110
70
60
19
17
30
27
28
21
82
73
118
108
77
68

Side
by side
78
70
108
106
61
60
17
15
27
28
20
21
78
73
110
109
65
63

▲ ▽: p <0.05▽▽ ▽: Female distance is longer than male

illuminance that could be inside the university building was set
at 10 lux. In all conditions, the subjects stood at a point about 60
cm away from the wall, and there were no other people within 8
m of the surroundings. After completing the position adjustmentof the four conditions of one interpersonal setting, they answered
the most easy-to-talk condition and the reason.
The experiment was carried out from 16:00 to 20:00 from
May to August 2018. The entrance hall is about 300 square
meters. During the experiment, daylight was blocked by blinds

at the opening, and the illuminance was adjusted by turning
off part of the ceiling lighting. The subjects were 2nd to 4th
graders of the Tokyo City University Architectural Department,
and it was confirmed beforehand that all the pairs of subjects
were familiar with each other, but were not yet friends. The
conversation partner was the same person in all settings for one
subject. A small height difference was set, which is 6–18 cm
between male and female subjects and within 10 cm between
subjects from the same sex. Fifty-one subjects participated inFig. 2 Reproduction of conversational situation based on average of interpersonal distance3

Table 3 Result of interpersonal distance t test (paired t-test)
Male
Common condition

Compared conditions

BrightFavorite opposite sex

Unfavorite opposite sex

Dark

Favorite opposite sex

Unfavorite opposite sex

BrightFavorite opposite sex

Same sex

Dark

Favorite opposite sex

Same sex

BrightUnfavorite opposite sex

Same sex

Dark

Unfavorite opposite sex

Same sex

Favorite opposite sex

Dark

BrightUnfavorite opposite sex

Dark

BrightSame sex

Dark

Bright** : The right condition is longer, and p<0.01 in the t test.

all the conditions. The order of the conditions performed varies
depending on the subjects.
After adjusting the position under each condition, thepositions of the feet of the subjects in a standing position were
measured, and the horizontal distance between the tops of theheads was obtained. There were no restrictions regarding whether
or not they could make physical contact, but some of theirclothes might have touched them when they stood side by side.

3. Results and discussion
3.1 Minimum interpersonal distance in face to face

Table 2 shows the average, standard deviation, and medianvalues of interpersonal distance (horizontal distance between
head and head center) under each condition. The average andmedian values are slightly different, but the tendencies arealmost identical. Although there are some individual differences,
the standard deviation is about the same as that of the paststudies10, 18）. In the following description, the average value isused as representative of each condition. Tables 2 and 3 show thet-test results between subjects sexes and between interpersonalsettings and lighting conditions respectively. Figure 2 displays
the reproduction photos of the conversation situation based on
the average of interpersonal distance under each condition.
From Table 2, it was found that female pairs were closest
to each other when they talked face to face. Followed by thefavorite opposite-sex pairs, male pairs, and not favorite oppositesex pairs in that order. The distance from the not favorite
opposite-sex pairs was about twice the distance between female
pairs. Regarding the distance between the favorite opposite-sex
pairs, male subjects were 85 cm in the bright situations and 77
cm in the dark situations, while female subjects were 79 cm inthe bright situations and 69 cm in the dark situations. For bothfavorite type and not favorite opposite sex, male evaluations wereslightly longer than female evaluations. The order of distances by
sex in this result is consistent with the past studies１–５）.
In any interpersonal setting, the distance was closer in thedark situation than the bright situation, and the difference
was the farthest at about 10 cm of the favorite opposite sex.
From Table 3, significant differences were found in the face to4Female

Face
Side
Face
Side
to face by side to face by side

**
**
**
**
**
**
*
*
*

**
**
**
**
**
**

**
**

**
**

**
**
**

**
**
*

**
* : The right condition is longer, and p<0.05 in the t test.
Table 4 Result of the most easy-to-talk condition(Ratio of subjects)
SubjectMale(n=25)

Conversational partner
Favorite opposite sex
Unfavorite opposite sex
Same sex
Favorite opposite sex

FemaleUnfavorite opposite sex(n=26)
Same sex
Favorite opposite sex
Allsubjects Unfavorite opposite sex(n=51) Same sex

Bright

Dark

Face
Side
to faceby side
16
12

Face
Side
to faceby side
40
32
48

8

16

28

44

44

4

8

8

15

12

65
12

35

27

27

54

42

4

0

12

14

22

53

22

22

27

29

49

43

4

4

Bold letters above 40%

face situation where the distances were closer than the brightsituation in all conditions other than the not favorite type byfemales. Generally, there is a tendency that the distance to a
stranger tends to be farther in a dark situation11, 14）, whereas
female friends and couples get closer to the dark situation13, 16, 17）.
The result of this experiment is similar to the latter, and it canbe considered that the relationship that they already knew eachother became accessible even in the dark situation.
The distance from the favorite opposite sex is close to the farphase (76 to 122 cm) of personal distance indicated by E.
T. Hall19） and corresponds to the classification for conversation
between friends and family. Nishide 20） indicated that theJapanese conversation area is about 50 to 150 cm, and when it
exceeds 80 cm, it tends to change to formal conversation. This
study also showed that the distance was almost similar whenpeople approached their favorite types of opposite sex. In thisexperiment, the difference between the interpersonal distanceof the favorite and not favorite opposite sex was about 40 cm,
whereas in the past studies, the difference between friendly(favorite) and unfriendly (not favorite) opposite sex was about
20 cm10, 18）, and the distance from the unknown opposite sex
was farther than the known opposite sex, which is 10 cm formales and 100 cm for females５）. As to why various interpersonal
distances were taken, it is presumed that the settings andplaces of the past experiments are not consistent with each
investigation and the unknown partners are not friends or a
couple but are acquaintances in this experiment.

Table 5 Reasons for easy-to-talk conditions(Total number of respondents, the inside of () is female)
Favorite opposite sex
BrightReasons
Easy to perceive the partner's expression

Dark

Unfavorite opposite sex
Bright

3(1)

3(3)

3(0)

4(2)

1(1) 14(8)To be able to talk with the partner closely2(2)1(1) 13(6)To be able to talk calmly

2(2)

7(3)

Desire to confirm the partner's appearance because of anxiety
Moderate distance is easy to take

1(1)

1(1)

To relieve tension or to be able to be in nature

2(2)

1(1)

3(1)

7(4)

Not to be anxious about the surrounding people

2(0)

5(3)

Easy to create a mood of conversation

4(1)The horizontal distances between two heads were generally
closer when side by side than when facing each other. When they
had a conversation side by side, female pairs were also closest toeach other, followed by the favorite opposite-sex pairs and malepairs, and not favorite opposite-sex pairs. The distance of malesubjects to the favorite opposite sex was 76 cm under brightsituations and 73 cm under dark situations. Female subjects
were 79 cm under bright situations and 73 cm under darksituations. Female subjects had farther interpersonal distancethan male subjects compared to both the favorite and not favorite
opposite sex, and they became particularly noticeable in the darksituations with not favorite types. Compared to the face to face
direction, male subjects side by side were closer while female
subjects were slightly farther. It is generally known that a male s
personal space is wider in the forward direction than female s
area５,９, 15）. Even when communicating, it is considered that malesubjects are trying to leave their partners when they face eachother. Although the distance is close under the darker situations
than the bright situations, the difference is not as pronounced
as when facing each other. Significant differences were foundonly in female evaluations of the favorite opposite sex (Table 3).
Conversely, in female evaluations of the not favorite opposite sex,
the average value was slightly larger in the dark situation.
After the experiment, female subjects were interviewed why
they took distance in the case of side by side for not favorite
types of opposite sex. As a result, the following comments
were obtained from multiple subjects: Desire to avoid contact
with males and Taking distance for the safety to confirm thebehaviors of the other person . Even if the distances between theheads are the same, the shortest distance between the body andthe body is close in side by side because the body is spreading
to the shoulder side. Therefore, it may be considered to keep a
distance in order to avoid body contact. Also, it is considered that
consciousness about safety is involved when the distance becomesa little wider under the dark situations for female subjects.
3.3 Easy-to-talk orientation and brightness

Among four conditions of the direction and the lighting inDark

21(12)

Not want to see each other face

3.2 M inimum interpersonal distance in side by side condition

Same sex
BrightFace Side Face Side Face Side Face Side Face Side Face Side
by
to
by
to
by
to
by
to
by
to
by
to
face side face side face side face side face side face side

Not to be too conscious of the partner because not facing each other

Unlikely to feel embarrassed with the partner

Dark

4(4)

8(3) 11(2)

5(5)

6(6)

5(4)

3(0)

6(6)

4(2)

4(2)

1(1)

3(1)

3(1)

1(1)

7(2)

1(0)

2(2)

2(0)

1(1)
1(0)
1(0)

1(0)

1(1)

each interpersonal setting, one situation was selected that wasmost easy to talk. Table 4 shows the result. It presents the stateof talking with the shortest distance under each condition. From
the table, a certain number of male subjects answered that dark
and side by side conditions were the easiest to talk, for boththe favorite and not favorite opposite sex. In the case of malepairs, bright situations were answered as easy to talk, and thereis hardly any difference when it comes to orientation. Female
subjects responded that dark and side by side conditions wereeasier to talk for the favorite opposite sex, and bright and face toface conditions were easier to talk for the not favorite opposite
sex. Both female and male pairs answered that they were easy totalk under bright situations.
Table 5 summarizes the reasons why they felt easy to talk at
the selected condition. Because it is based on free description,
it shows not the answer ratio but the number of subjects. The
numbers in parentheses indicate the number of female subjects.
The major reasons why dark and side-by-side conditions wereeasy to talk to for the favorite opposite sex are as follows: Not
to be too conscious of the partner because not facing each other ,To be able to talk with the partner closely , To relieve tension
or to be able to be in nature , and Not to be anxious about thesurrounding people . In the case of the not favorite opposite sex
with dark and side by side condition, Not want to see each otherface is mentioned, and the explanations that they preferred not
looking at their partners faces are quite different. On the other
hand, the reasons why female subjects preferred the face to face
direction for the not favorite opposite sex are described as Desire
to confirm the partner s appearance because of anxiety andModerate distance is easy to take . The reason that same sex
favored brightness and face to face direction is described because
it is easy to confirm the expression of the partner.
From these results, it was found for the favorite opposite sex
that men were easy to approach side by side in the dark situation
while women prefer face to face in the dark situation. It wasalso found that both men and women were the easiest to talk indark and side by side condition. It can be said that it is possible
to approach without being too conscious of the partner and5to talk calmly. People who already have romantic relationships
such as couples had confirmed the tendency to approach side
by side16, 17）, but it turned out that the condition was preferred
even in the very early romance period. A situation that is easy
for conversation encourages distance to be close, and a situation
where it is comfortable even if it is close to the partner promotesa more intimate conversation. When both have romantic feelings
for each other, the increase in one s nonverbal intimacy behavior
is often returned from the other party in the same way８, 15）, so
the proximity of each other may be promoted. Moreover, it canbe predicted that the psychological resistance of approaching
the partner is also relatively small in the dark and side by side
situation. Sommer９） mentioned that it was the easiest to talkwhen partners sit at an angle of 90 degrees. Since this researchassumed a conversation while standing, it was not set to face at
90 degrees, but it is necessary to examine how to face each other.

4. Conclusion
In this research, an experiment was conducted to ascertain
the extent a conversation can be made in close proximity to the
opposite sex of an acquaintance having romantic intentions. In
the experiment, instead of confirming the presence or absence ofreal romantic feelings, the subjects imagined those situations intheir minds. As a result, the distance to the favorite opposite sex
was the closest when men were side by side with dark lighting
and women were facing each other with dark lighting. At thistime, the average horizontal distance between the partners heads
was about 70 cm. Both men and women also evaluated that they
were the easiest to talk when it was dark and side by side. Theinterpersonal distance was not as close as that of female pairs,
but it was similar or closer to that of male pairs and clearly closer
than the not favorite opposite sex. The distance from the favorite
opposite sex was strongly influenced by the lighting in thecase of face to face direction, and approaches made in the darksituation were about 10 cm shorter than the bright situation.
The condition of favorite or not favorite opposite sex inthis experiment was assumed in the subjects minds. It is noteasy to grasp the interpersonal distance based on real romantic
intentions, but examining the probability of setting is a future
research topic. Also, in this experiment, young Japanese university
students were adopted as subjects, but it is considered that there
are also differences depending on age, personality and culture.
Although interpersonal distance research findings exist
enormously up to now, investigations that examined romance
consciousness, body orientation and lighting as variables were notfound internationally. These results seem to be usable for settinginterpersonal distance that is comfortable to the opposite sex who
is just an acquaintance but not yet a friend. It could also be utilized
for planning restaurants and entertainment halls for people ofopposite sex who want to promote romantic relationships in agentle manner because of passive personality. Finally, although
this study was set up for romantic relationships with the opposite
6sex, this does not cover all combinations of romantic relationships.
Diversity in romantic feelings should be respected and individual
feelings and interpersonal relationships should be nurtured.
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（2022年９月９日原稿受理，2023年１月28日採用決定）