Emoji are widely treated as compact affective tokens whose meaning is summarised by a single sentiment score. We argue that this picture is incomplete. From a corpus of 16{,}575 English tweets and a per-emoji metric we call stability delta (within-class minus between-class cosine similarity of sentence embeddings), we show that emojis used in tightly clustered topical contexts also exhibit more polarised crowd-sourced sentiment, not less. Validated against the Kralj Novak et al.\ (2015) sentiment lexicon, the central correlation is Spearman ρ=+0.361 (Holm p=0.015, 95% bootstrap CI [+0.10,+0.59]); against the independent Ferré et al.\ (2025) Spanish 13-emotion ratings, ρ=+0.509 (p=0.0003). The result survives permutation testing, BCa bootstrap, leave-one-out jackknife, partial correlation controlling for emoji frequency, and Holm correction across a four-test family. Topical coherence and affective dispersion are distinct dimensions of emoji meaning. As a downstream check we report leakage-free five-fold cross-validation results for sarcasm classification on the Emoji Sarcasm Dataset; all three baselines (a gated multimodal architecture, fine-tuned BERTweet features, and fine-tuned RoBERTa features) score above 0.97 macro F1, indicating the dataset has saturating emoji-label cues. We frame the classifier as supporting evidence rather than the contribution.
Figures & tables
Figure 1: VADER compound score distributions by emoji position and role (substitutive vs. additive). Substitutive emojis produce more polarised distributions across all three positions.
Figure 2: Mean VADER compound score for the top-20 emojis across positional contexts (start, middle, end). Right column shows raw frequency. Individual emojis exhibit marked affective shifts depending on position; where an emoji sits predicts its sentiment as strongly as which emoji it is.
Emoji (description)
Within
Between
Δ
Collision
0.409
0.172
0.237
Fire
0.332
0.140
0.192
Pointing-down
0.305
0.152
0.153
Astonished face
0.121
0.101
0.021
Loudly crying face
0.143
0.124
0.019
Confused face
0.124
0.109
0.014
Table 1: Top and bottom emojis ranked by stability delta. “Within” and “Between” are mean pairwise cosine similarities within and across emoji classes.
Test
ρ
Pct. CI (95%)
BCa CI (95%)
Perm. p
τb
Partial ρ (freq)
Holm p
Δ vs. Kralj Novak sentiment
+0.408
[+0.16,+0.60]
[+0.16,+0.60]
0.0008
+0.258
+0.423
0.005
Δ vs. Kralj Novak variance (primary)
+0.361
[+0.10,+0.59]
[+0.09,+0.58]
0.005
+0.261
+0.370
0.015
Sarcasm rate vs. p(neg)
−0.286
[−0.57,+0.02]
[−0.55,+0.02]
0.028
−0.227
−0.280
0.051
Sarcasm rate vs. Kralj Novak sentiment
+0.291
[−0.01,+0.57]
[−0.01,+0.55]
0.029
+0.234
+0.289
0.051
Table 2: Kralj Novak (2015) validation, n=59 matched emojis. Holm correction applied across the family of four tests. Significance markers refer to Holm-corrected p -values.
Figure 3: Contextual stability is positively associated with affective dispersion. Left: stability Δ vs. Kralj Novak sentiment variance ( n=59 , Spearman ρ=+0.361 , BCa 95=[+0.089,+0.581] , Holm p=.015 ). Right: stability Δ vs. number of strongly evoked emotions in Ferré et al. ( n=47 , ρ=+0.509 , p=.0003 ). Emojis used in more topically coherent contexts evoke broader, not narrower, affective responses.
Figure 4: Stability delta versus Kralj Novak sentiment score (left) and sentiment variance (right). Red lines are OLS fits. Both relationships are positive and Holm-significant.
Likert threshold
ρ
p
Sig.
≥2.0
+0.606
6.0×10−6
≥2.5 (primary)
+0.509
2.6×10−4
≥3.0
+0.458
1.2×10−3
**
≥3.5
+0.415
3.7×10−3
**
Table 3: Stability delta vs. number of strongly evoked emotions in Ferré 2025, with threshold sensitivity. n=47 matched emojis throughout.
Model
Macro F1
Sarc. F1
GEMA
.985±.007
.982±.008
BERTweet
.974±.002
.967±.002
RoBERTa
.991±.001
.988±.001
Table 4: Five-fold stratified CV on the English Twitter partition ( n=16,587 , mean ± SD). Full 5-metric evaluation reported in Appendix F .
Appendix figures & tables4 assets
Supplementary material from the paper’s appendix.
Appendix
Model
Acc.
Macro F1
Sarc. F1
AUC
MCC
GEMA
.986±.006
.985±.007
.982±.008
.999±.000
.970±.013
BERTweet
.975±.002
.974±.002
.967±.002
.997±.001
.948±.003
RoBERTa
.991±.001
.991±.001
.988±.001
.999±.000
.982±.002
Appendix
Table 5: Full five-fold stratified cross-validation results on the English-filtered Twitter partition ( n=16,587 ). Values show mean ± standard deviation across folds.
Source
Test
n
ρ
p
Czestochowska
Δ vs. description entropy
59
−0.087
0.51
Czestochowska
Δ vs. unique words
59
−0.029
0.83
EmojiNet
Δ vs. sense count
62
−0.119
0.36
EmojiNet
Δ vs. keyword count
62
+0.075
0.56
Appendix
Table 6: Sanity checks against decontextualised ambiguity Czestochowska et al. (2022) and dictionary polysemy Wijeratne et al. (2017) .
Position
Count
VADER
TextBlob
Start
2,188
+0.267
+0.190
Middle
4,728
+0.0667
+0.116
End
9,659
−0.018
+0.032
Appendix
Table 7: Mean sentiment scores by emoji position (VADER and TextBlob, scored on emoji-free text).
Component / Parameter
Specification / Value
Architecture & Branches
Text Encoder
BiGRU over MiniLM embeddings, BERT [CLS]
Emoji Branch
Mean Kralj Novak sentiment, normalized emoji counts